Treatment of filarial diseases

ABSTRACT

The present invention pertains to prevention of and/or treatment for filariasis. In particular, the present invention pertains to the use of tylosin A and its analogs and derivatives to prevent or treat filarial worm infection and/or diseases associated with filarial worm infection. The present invention also pertains to pharmaceutical compositions comprising tylosin A or an analog or derivative thereof for use in preventing or treating filarial worm infection and/or diseases associated with filarial worm infection.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.62/101,484 filed Jan. 9, 2015, the entire contents of which areincorporated herein by reference.

JOINT RESEARCH AGREEMENT

Subject matter disclosed in this application was made by or on behalf ofAbbVie Inc. and/or Liverpool School of Tropical Medicine, whom areparties to a joint research agreement that was in effect on or beforethe effective filing date of this application, and such subject matterwas made as a result of activities undertaken within the scope of thejoint research agreement.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

TECHNICAL FIELD

The present invention relates to prevention of and/or treatment forfilarial worm infections and diseases caused by filarial worm infection.The present invention relates to the use of tylosin A and its analogsand derivatives to prevent or treat filarial worm infection and/ordiseases associated with filarial worm infection. The present inventionalso relates to pharmaceutical compositions comprising tylosin A or ananalog or derivative thereof for use in preventing or treating filarialworm infection and/or diseases associated with filarial worm infection.

BACKGROUND

Wolbachia is a genus of bacteria that infects arthropods, includinginsects and crusteans, and filarial worms such as Onchocerca volvulus,Wuchereria bancrofti, Brugia malayi, and Brugia timori. The bacteriareside in cytoplasmic vacuoles and are essential for development,reproduction and long-term survival of filarial worms.

Onchocerca volvulus is a causative agent of onchocerciasis, or riverblindness, in humans. Manifestations of onchocerciasis result primarilyfrom the intense inflammatory reaction to Wolbachia bacteria releasedinto the skin and eyes upon the death of microfilaria. Onchocerciasisaffects up to 37 million people worldwide and is most abundant inAfrica.

Wuchereria bancrofti, Brugia malayi, and Brugia timori are causativeagents of lymphatic filariasis, or elephantiasis, in humans. Peoplesuffering with lymphatic filariasis can develop hydrocele and lymphedemaleading to elephantiasis. It is estimated that up to 120 million peoplein 83 countries worldwide are affected by lymphatic filariasis.

Two of the major constraints of treatment of filarial diseases are (i)the absence of a macrofilaricidal drug (or for onchocerciasis, one whichpermanently sterilizes the worm) and (ii) the risk of worms developingdrug-resistance. For example, currently available treatments foronchocerciasis include ivermectin, which kills worm larvae, but haslittle or no activity against adult Onchocerca volvulus parasites. Thus,infected patients must be retreated with ivermectin for several yearsuntil the adult worms die naturally. The most commonly used doseinterval is 12 months; however, retreatment with ivermectin may beconsidered at intervals as short as 3 months. In addition, there arealso potential signs of resistance to ivermectin within the parasite ina few areas. Osei-Atweneboana M Y, et al. (2011) Phenotypic Evidence ofEmerging Ivermectin Resistance in Onchocerca volvulus. PLoS Negl TropDis 5(3): e998. In addition, there is a danger in treating patientsco-infected with both (i) Wuchereria bancrofti, Brugia malayi, Brugiatimori, and/or Onchocerca volvulus; and (ii) Loa loa with ivermectin. Insuch co-infected patients, ivermectin treatment can cause severereactions, including encephalopathy, leading to coma or even death.Thus, alternative, and more effective, treatments for filarial wormdiseases and, in particular, onchocerciasis and lymphatic filariasis areneeded.

Antibiotics, such as doxycycline, minocycline, and rifampicin, have beendemonstrated to be effective against Wolbachia. Taylor et al., (2005)Lancet. 365(9477):2116-2121 and Townson S, et al., (2006) Filaria J.5:4. However, it has been reported that other classes of antibiotics,such as penicillins, aminoglycosides, and macrolides are ineffective atdepleting Wolbachia from filariae. Hoerauf A, et al. (1999) Journal ofClinical Investigation 103(1):11-18 and Hoerauf A, et al. (2000) TropMed Int Health 5(4):275-279.

Existing anti-Wolbachia drugs are non-optimal; they require a relativelylong course of treatment (˜4 weeks) and often exclude certain subjects,including pregnant women and children under the age of 9 (e.g., withtetracyclines). Thus, there exists a need for better anti-Wolbachiatreatments, such as those providing a shorter treatment regimen (e.g., 7days or less) and usable in currently restricted populations (Taylor etal. Parasitology, 141(1):119-27).

SUMMARY OF THE INVENTION

In one aspect, the present invention includes a method of treating asubject infected with a filarial worm. In certain embodiments, themethod includes administering a therapeutically effective amount of amacrolide antibiotic to the subject. In certain embodiments, themacrolide antibiotic is tylosin A, a tylosin A analog, a tylosin Aderivative, or a salt thereof. In certain embodiments, the filarial wormis infected with a bacterium belonging to the genera Wolbachia.

In one aspect, the present invention includes a method of treating asubject infected with a filarial worm. In certain embodiments, themethod includes administering a therapeutically effective amount of acompound of Formula (I), (I-1), (II), (III), (IV), (V), (VI), (VII),(VIII), (IX), or a pharmaceutically acceptable salt thereof, to thesubject. In certain embodiments, the filarial worm is Onchocercavolvulus. In certain embodiments, the filarial worm is Wuchereriabancrofti. In certain embodiments, the filarial worm is Brugia malayi.In certain embodiments, the filarial worm is Brugia timori. In certainembodiments, the filarial worm is Dirofilaria immitis, which is acausative agent of canine cardiovascular dirofilariasis, or canineheartworm disease. In certain embodiments, the filarial worm is infectedwith a bacterium belonging to the genera Wolbachia.

In one aspect, the present invention includes a method of treating ahuman subject co-infected, or suspected to be co-infected, with (i)Wuchereria bancrofti, Brugia malayi, Brugia timori, and/or Onchocercavolvulus; and (ii) Loa loa. In certain embodiments, the method includesadministering a therapeutically effective amount of a compound ofFormula (I), (I-1), (II), (III), (IV), (V), (VI), (VII), (VIII), (IX),or a pharmaceutically acceptable salt thereof, to the human subject. Incertain embodiments, the treatment selectively kills Wuchereriabancrofti, Brugia malayi, Brugia timori, and/or Onchocerca volvulusmicrofilariae but not Loa loa microfilariae. In this way, adverseeffects associated with killing vast numbers of Loa loa microfilariaecan be avoided. In certain embodiments, the human subject has beendiagnosed with a Loa loa infection using a standard diagnostic test(e.g., an assessment of Loa loa microfilariae in the subject's blood).In certain other embodiments, the human subject is suspected of having aLoa loa infection. For example, the human subject may come from a regionco-endemic for loiasis and lymphatic filariasis or onchocerciasis.

In another aspect, the present invention includes a method of inhibitinggrowth of a filarial worm and/or killing a filarial worm. In certainembodiments, the method includes contacting a filarial worm with amacrolide antibiotic. In certain embodiments, the macrolide antibioticis tylosin A, a tylosin A analog, a tylosin A derivative, or a saltthereof. In certain embodiments, the filarial worm is infected with abacterium belonging to the genera Wolbachia.

In another aspect, the present invention includes a method of inhibitinggrowth of a filarial worm and/or killing a filarial worm. In certainembodiments, the method includes contacting a filarial worm with acompound of Formula (I), (I-1), (II), (III), (IV), (V), (VI), (VII),(VIII), (IX), or a pharmaceutically acceptable salt thereof, in anamount effective to inhibit growth of the filarial worm and/or kill thefilarial worm. In certain embodiments, the filarial worm is Onchocercavolvulus. In certain embodiments, the filarial worm is Wuchereriabancrofti. In certain embodiments, the filarial worm is Brugia malayi.In certain embodiments, the filarial worm is Brugia timori. In certainembodiments, the filarial worm is Dirofilaria immitis. In certainembodiments, the filarial worm is infected with a bacterium belonging tothe genera Wolbachia.

In another aspect, the present invention includes a method of treating asubject having a Wolbachia infection. In certain embodiments, the methodincludes administering a therapeutically effective amount of a macrolideantibiotic to the subject. In certain embodiments, the Wolbachiainfection is associated with a filarial worm infection.

In another aspect, the present invention includes a method of treating asubject having a Wolbachia infection. In certain embodiments, the methodincludes administering a therapeutically effective amount of a compoundof Formula (I), (I-1), (II), (III), (IV), (V), (VI), (VII), (VIII),(IX), or a pharmaceutically acceptable salt thereof, to the subject. Incertain embodiments, the Wolbachia infection is associated with afilarial worm infection.

In another aspect, the present invention includes a method of inhibitinggrowth of bacteria associated with a filarial worm and/or killingbacteria associated with a filarial worm. In certain embodiments, themethod includes contacting the bacteria associated with the filarialworm with a macrolide antibiotic in an amount effective to inhibitgrowth of the bacteria and/or kill the bacteria. In certain embodiments,the macrolide antibiotic is tylosin A, a tylosin A analog, a tylosin Aderivative, or a salt thereof. In certain embodiments, the bacteriabelong to the genera Wolbachia.

In another aspect, the present invention includes a method of inhibitinggrowth of bacteria associated with a filarial worm and/or killingbacteria associated with a filarial worm. In certain embodiments, themethod includes contacting the bacteria associated with the filarialworm with a compound of Formula (I), (I-1), (II), (III), (IV), (V),(VI), (VII), (VIII), (IX), or a pharmaceutically acceptable saltthereof, in an amount effective to inhibit growth of the bacteria and/orkill the bacteria. In certain embodiments, the bacteria belong to thegenera Wolbachia. In certain embodiments, the filarial worm isOnchocerca volvulus. In certain embodiments, the filarial worm isWuchereria bancrofti. In certain embodiments, the filarial worm isBrugia malayi. In certain embodiments, the filarial worm is Brugiatimori. In certain embodiments, the filarial worm is Dirofilariaimmitis.

In another aspect, the present invention includes a method of treating adisease caused by a filarial worm infection. In certain embodiments, themethod includes administering a therapeutically effective amount of amacrolide antibiotic to a subject having a disease caused by a filarialworm infection. In certain embodiments, the macrolide antibiotic istylosin A, a tylosin A analog, a tylosin A derivative, or a saltthereof. In certain embodiments, the disease is heartworm disease. Inother embodiments, the disease is onchocerciasis. In still otherembodiments, the disease is lymphatic filariasis.

In another aspect, the present invention includes a method of treating adisease caused by a filarial worm infection. In certain embodiments, themethod includes administering a therapeutically effective amount of acompound of Formula (I), (I-1), (II), (III), (IV), (V), (VI), (VII),(VIII), (IX), or a pharmaceutically acceptable salt thereof, to asubject having a disease caused by a filarial worm infection. In certainembodiments, the disease is heartworm disease. In other embodiments, thedisease is onchocerciasis. In still other embodiments, the disease islymphatic filariasis.

In another aspect, the present invention includes a method of treatingheartworm disease. In certain embodiments, the method includesadministering a therapeutically effective amount of a macrolideantibiotic to a subject having heartworm disease. In certainembodiments, the macrolide antibiotic is tylosin A, a tylosin A analog,a tylosin A derivative, or a salt thereof. In certain embodiments, theheartworm disease is caused by infections of Dirofilaria immitis. Incertain embodiments, the subject is an animal, such as a dog. In certainembodiments, the animal is characterized as being asymptomatic to havingmild heartworm disease. In certain embodiments, the animal ischaracterized as having moderate heartworm disease. In certainembodiments, the animal is characterized as having severe heartwormdisease.

In another aspect, the present invention includes a method of treatingheartworm disease. In certain embodiments, the method includesadministering a therapeutically effective amount of a compound ofFormula (I), (I-1), (II), (III), (IV), (V), (VI), (VII), (VIII), (IX),or a pharmaceutically acceptable salt thereof, to a subject havingheartworm disease. In certain embodiments, the heartworm disease iscaused by infections of Dirofilaria immitis. In certain embodiments, thesubject is an animal, such as a dog. In certain embodiments, the animalis characterized as being asymptomatic to having mild heartworm disease.In certain embodiments, the animal is characterized as having moderateheartworm disease. In certain embodiments, the animal is characterizedas having severe heartworm disease.

In another aspect, the present invention includes a method of treatingonchocerciasis. In certain embodiments, the method includesadministering a therapeutically effective amount of a macrolideantibiotic to a subject having onchocerciasis. In certain embodiments,the macrolide antibiotic is tylosin A, a tylosin A analog, a tylosin Aderivative, or a salt thereof. In certain embodiments, theonchocerciasis is due to the filarial worm parasite Onchocerca volvulus.

In another aspect, the present invention includes a method of treatingonchocerciasis. In certain embodiments, the method includesadministering a therapeutically effective amount of a compound ofFormula (I), (I-1), (II), (III), (IV), (V), (VI), (VII), (VIII), (IX),or a pharmaceutically acceptable salt thereof, to a subject havingonchocerciasis. In certain embodiments, the onchocerciasis is due to thefilarial worm parasite Onchocerca volvulus.

In another aspect, the present invention includes a method of treatinglymphatic filariasis. In certain embodiments, the method includesadministering a therapeutically effective amount of a macrolideantibiotic to a subject having lymphatic filariasis. In certainembodiments, the macrolide antibiotic is tylosin A, a tylosin A analog,a tylosin A derivative, or a salt thereof. In certain embodiments, thelymphatic filariasis is due to the filarial worm parasite Wuchereriabancrofti. In certain embodiments, the lymphatic filariasis is due tothe filarial worm parasite Brugia malayi. In certain embodiments, thelymphatic filariasis is due to the filarial worm parasite Brugia timori.

In another aspect, the present invention includes a method of treatinglymphatic filariasis. In certain embodiments, the method includesadministering a therapeutically effective amount of a compound ofFormula (I), (I-1), (II), (III), (IV), (V), (VI), (VII), (VIII), (IX),or a pharmaceutically acceptable salt thereof, to a subject havinglymphatic filariasis. In certain embodiments, the lymphatic filariasisis due to the filarial worm parasite Wuchereria bancrofti. In certainembodiments, the lymphatic filariasis is due to the filarial wormparasite Brugia malayi. In certain embodiments, the lymphatic filariasisis due to the filarial worm parasite Brugia timori.

In another aspect, the present invention includes a method ofeliminating adult filarial worms. In certain embodiments, the methodincludes administering a therapeutically effective amount of a macrolideantibiotic to a subject infected with adult filarial worms. In certainembodiments, the macrolide antibiotic is tylosin A, a tylosin A analog,a tylosin A derivative, or a salt thereof. In certain embodiments, thefilarial worms are Onchocerca volvulus worms. In certain embodiments,the filarial worms are Wuchereria bancrofti worms. In certainembodiments, the filarial worms are Brugia malayi worms. In certainembodiments, the filarial worms are Brugia timori worms. In certainembodiments, the filarial worms are Dirofilaria immitis worms.

In another aspect, the present invention includes a method ofeliminating adult filarial worms. In certain embodiments, the methodincludes administering a therapeutically effective amount of a compoundof Formula (I), (I-1), (II), (III), (IV), (V), (VI), (VII), (VIII),(IX), or a pharmaceutically acceptable salt thereof, to a subjectinfected with adult filarial worms. In certain embodiments, the filarialworms are Onchocerca volvulus worms. In certain embodiments, thefilarial worms are Wuchereria bancrofti worms. In certain embodiments,the filarial worms are Brugia malayi worms. In certain embodiments, thefilarial worms are Brugia timori worms. In certain embodiments, thefilarial worms are Dirofilaria immitis worms.

In another aspect, the present invention includes a method ofsterilizing adult filarial worms. In certain embodiments, the methodincludes administering a therapeutically effective amount of a macrolideantibiotic to a subject infected with filarial worms. In certainembodiments, the macrolide antibiotic is tylosin A, a tylosin A analog,a tylosin A derivative, or a salt thereof. In certain embodiments, thefilarial worms are Onchocerca volvulus worms. In certain embodiments,the filarial worms are Wuchereria bancrofti worms. In certainembodiments, the filarial worms are Brugia malayi worms. In certainembodiments, the filarial worms are Brugia timori worms. In certainembodiments, the filarial worms are Dirofilaria immitis worms.

In another aspect, the present invention includes a method ofsterilizing adult filarial worms. In certain embodiments, the methodincludes administering a therapeutically effective amount of a compoundof Formula (I), (I-1), (II), (III), (IV), (V), (VI), (VII), (VIII),(IX), or a pharmaceutically acceptable salt thereof, to a subjectinfected with adult filarial worms. In certain embodiments, the filarialworms are Onchocerca volvulus worms. In certain embodiments, thefilarial worms are Wuchereria bancrofti worms. In certain embodiments,the filarial worms are Brugia malayi worms. In certain embodiments, thefilarial worms are Brugia timori worms. In certain embodiments, thefilarial worms are Dirofilaria immitis worms.

In another aspect, the present invention includes a method of decreasingmicrofilariae in a subject infected with filarial worms. In certainembodiments, the method includes administering a therapeuticallyeffective amount of a macrolide antibiotic to the subject. In certainembodiments, the macrolide antibiotic is tylosin A, a tylosin A analog,a tylosin A derivative, or a salt thereof. In certain embodiments, thefilarial worms are Onchocerca volvulus worms. In certain embodiments,the filarial worms are Wuchereria bancrofti worms. In certainembodiments, the filarial worms are Brugia malayi worms. In certainembodiments, the filarial worms are Brugia timori worms. In certainembodiments, the filarial worms are Dirofilaria immitis worms.

In another aspect, the present invention includes a method of decreasingmicrofilariae in a subject infected with filarial worms. In certainembodiments, the method includes administering a therapeuticallyeffective amount of a compound of Formula (I), (I-1), (II), (III), (IV),(V), (VI), (VII), (VIII), (IX), or a pharmaceutically acceptable saltthereof, to the subject. In certain embodiments, the filarial worms areOnchocerca volvulus worms. In certain embodiments, the filarial wormsare Wuchereria bancrofti worms. In certain embodiments, the filarialworms are Brugia malayi worms. In certain embodiments, the filarialworms are Brugia timori worms. In certain embodiments, the filarialworms are Dirofilaria immitis worms.

In one aspect, the present invention includes a method of treating asubject having a disease caused by a filarial worm infection byadministering an antibiotic compound for a treatment duration of no morethan fourteen (14) days. In certain embodiments, the treatment durationis no more than seven (7) days, including but not limited to, no morethan six (6) days, no more than five (5) days, no more than four (4)days, no more than three (3) days, no more than (2) days, no more thanone (1) day, e.g., the treatment duration being seven (7) days. Incertain embodiments, the method includes administering a therapeuticallyeffective amount of a macrolide antibiotic to a subject having a diseasecaused by a filarial worm infection. In certain embodiments, themacrolide antibiotic is tylosin A, a tylosin A analog, a tylosin Aderivative, or a salt thereof. In certain embodiments, the methodincludes administering a therapeutically effective amount of a compoundof Formula (I), (I-1), (II), (III), (IV), (V), (VI), (VII), (VIII),(IX), or a pharmaceutically acceptable salt thereof, to a subject havinga disease caused by a filarial worm infection. In certain embodiments,the disease is heartworm disease. In other embodiments, the disease isonchocerciasis. In still other embodiments, the disease is lymphaticfilariasis.

In one aspect, the present invention includes a method of treating asubject with a filarial worm infection by administering an antibioticcompound for a treatment duration of no more than fourteen (14) days. Incertain embodiments, the treatment duration is no more than seven (7)days, including but not limited to, no more than six (6) days, no morethan five (5) days, no more than four (4) days, no more than three (3)days, no more than (2) days, no more than one (1) day, e.g., thetreatment duration being seven (7) days. In certain embodiments, themethod includes administering a therapeutically effective amount of amacrolide antibiotic to the subject. In certain embodiments, themacrolide antibiotic is tylosin A, a tylosin A analog, a tylosin Aderivative, or a salt thereof. In certain embodiments, the methodincludes administering a therapeutically effective amount of a compoundof Formula (I), (I-1), (II), (III), (IV), (V), (VI), (VII), (VIII),(IX), or a pharmaceutically acceptable salt thereof, to the subject. Incertain embodiments, the filarial worm is Onchocerca volvulus. Incertain embodiments, the filarial worm is Wuchereria bancrofti. Incertain embodiments, the filarial worm is Brugia malayi. In certainembodiments, the filarial worm is Brugia timori. In certain embodiments,the filarial worm is Dirofilaria immitis. In certain embodiments, thefilarial worm is infected with a bacterium belonging to the generaWolbachia.

These and other objects of the invention are described in the followingparagraphs. These objects should not be deemed to narrow the scope ofthe invention.

DETAILED DESCRIPTION OF THE INVENTION

This detailed description is intended only to acquaint others skilled inthe art with the present invention, its principles, and its practicalapplication so that others skilled in the art may adapt and apply theinvention in its numerous forms, as they may be best suited to therequirements of a particular use. This description and its specificexamples are intended for purposes of illustration only. This invention,therefore, is not limited to the embodiments described in this patentapplication, and may be variously modified.

A. DEFINITIONS

As used in the specification and the appended claims, unless specifiedto the contrary, the following terms have the meaning indicated:

The term “acyl” means an alkyl group, as defined herein, appended to theparent molecular moiety through a carbonyl group, as defined herein.Representative examples of acyl include, but are not limited to, acetyl,1-oxopropyl, 2,2-dimethyl-1-oxopropyl, 1-oxobutyl, and 1-oxopentyl.

The term “alkenyl” means a straight or branched hydrocarbon chaincontaining one or more carbon-carbon double bonds and, typically, from 2to 10 carbon atoms. Representative examples of alkenyl include, but arenot limited to, ethenyl, 2-propenyl, 2-methyl-2-propenyl, 3-butenyl,4-pentenyl, 5-hexenyl, 2-heptenyl, 2-methyl-1-heptenyl, and 3-decenyl.

The term “alkoxy” means an alkyl group, as defined herein, appended tothe parent molecular moiety through an oxygen atom. Representativeexamples of alkoxy include, but are not limited to, methoxy, ethoxy,propoxy, 2-propoxy, butoxy, tert-butoxy, pentyloxy, and hexyloxy.

The term “alkyl” means a straight or branched saturated hydrocarbonchain, typically containing from 1 to 10 carbon atoms. Representativeexamples of alkyl include, but are not limited to, methyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl,isopentyl, neopentyl, n-hexyl, 3-methylhexyl, 2,2-dimethylpentyl,2,3-dimethylpentyl, n-heptyl, n-octyl, n-nonyl, and n-decyl. In certaininstances, the hydrogen atoms of the alkyl groups may be optionallysubstituted by one or more substituents, including, but not limited to,acyl, alkoxy, alkynyl, carboxy, halogen, and hydroxy.

The term “lower alkyl” or “C₁-C₆-alkyl” means a straight or branchedhydrocarbon chain containing from 1 to 6 carbon atoms. In someinstances, the number of carbon atoms in a hydrocarbon substituent(e.g., alkyl, alkenyl, alkynyl, aryl, or cycloalkyl) is indicated by theprefix “C_(x)-C_(y)—”, wherein x is the minimum and y is the maximumnumber of carbon atoms in the substituent. Thus, for example,“C₁-C₆-alkyl” refers to an alkyl substituent containing from 1 to 6carbon atoms. Likewise, “C₆-C₁₀-aryl” refers to an aryl substituentcontaining from 6 to 10 carbon ring atoms. Similarly, “C₃-C₈-cycloalkyl”refers to a cycloalkyl substituent containing from 3 to 8 carbon ringatoms.

The term “alkylene” means a divalent group derived from a straight orbranched hydrocarbon chain, typically containing 1 to 10 carbon atoms.Representative examples of alkylene include, but are not limited to,—CH₂—, —CH₂CH₂—, —CH₂CH₂CH₂—, —CH₂CH₂CH₂CH₂—, and —CH₂CH(CH₃)CH₂—.

The term “alkynyl” means a straight or branched hydrocarbon chaincontaining one or more carbon-carbon triple bonds and, typically, from 2to 10 carbon atoms. Representative examples of alkynyl include, but arenot limited to, ethynyl, 2-propynyl, 3-propynyl, 2-butynyl, and3-butynyl and the like.

The term “aryl” means an aromatic carbocyclyl containing from 6 to 14carbon ring atoms. An aryl may be monocyclic or polycyclic (i.e., maycontain more than one ring). In the case of a polycyclic aryl, only onering of the polycyclic system is required to be aromatic while theremaining ring(s) may be saturated, partially saturated or unsaturated.Representative examples of aryl include, but are not limited to, phenyl,naphthalenyl, indenyl, indanyl, and tetrahydronapthyl. Unless otherwisespecified herein, the aryl groups can be substituted or unsubstituted.Thus, the hydrogen atoms of the aryl groups may be optionallysubstituted by one or more substituents, including, but not limited to,acyl, alkenyl, alkoxy, alkyl, alkynyl, carboxy, haloalkyl, halogen,hydroxy, and hydroxyalkyl.

The term “arylalkyl” means an aryl group, as defined herein, appended tothe parent molecular moiety through an alkylene group, as definedherein. Representative examples of arylalkyl include, but are notlimited to, benzyl, 2-phenylethyl, 3-phenylpropyl, and2-naphth-2-ylethyl.

The term “carbocyclyl” means a saturated cyclic, partially saturatedcyclic, or completely unsaturated cyclic hydrocarbyl substituentcontaining from 3 to 14 carbon ring atoms (“ring atoms” are the atomsbound together to form the ring or rings of a cyclic substituent). Acarbocyclyl may be a single-ring (monocyclic) or polycyclic ringstructure.

The term “carbonyl” means a —C(O)— group.

The term “carboxy” means a —CO₂H group.

The term “cycloalkyl” means a saturated cyclic hydrocarbyl substituentcontaining from 3 to 14 carbon ring atoms. A cycloalkyl may be a singlecarbon ring, which typically contains from 3 to 8 carbon ring atoms andmore typically from 3 to 6 ring atoms. Examples of single-ringcycloalkyls include, but are not limited to, cyclopropyl, cyclobutyl,cyclopentyl, and cyclohexyl. A cycloalkyl may alternatively bepolycyclic or contain more than one ring. Examples of polycycliccycloalkyls include bridged, fused, and spirocyclic carbocyclyls. Unlessotherwise specified herein, the cycloalkyl groups can be substituted orunsubstituted. Thus, the hydrogen atoms of the cycloalkyl groups may beoptionally substituted by one or more substituents, including, but notlimited to, acyl, alkenyl, alkoxy, alkyl, alkynyl, carboxy, haloalkyl,halogen, hydroxy, and hydroxyalkyl.

The term “cycloalkylalkyl” means a cycloalkyl group, as defined herein,appended to the parent molecular moiety through an alkylene group, asdefined herein. Representative examples of cycloalkylalkyl include, butare not limited to, cyclopropylmethyl, 2-cyclobutylethyl,cyclopentylmethyl, cyclohexylmethyl, and 4-cycloheptylbutyl.

The term “halo” or “halogen” means an atom selected from fluorine,chlorine, bromine, and iodine.

The term “haloalkyl” means an alkyl group, as defined herein, in whichone or more hydrogen atoms are replaced by halogen. Representativeexamples of haloalkyl include, but are not limited to, chloromethyl,2-fluoroethyl, 2,2,2-trifluoroethyl, trifluoromethyl, difluoromethyl,pentafluoroethyl, 2-chloro-3-fluoropentyl, and trifluoropropyl such as3,3,3-trifluoropropyl.

The term “heteroaryl” means an aromatic heterocyclyl containing from 5to 14 ring atoms. A heteroaryl may be monocyclic or polycyclic (i.e.,may contain more than one ring). In the case of a polycyclic heteroaryl,only one ring of the polycyclic system is required to be aromatic whilethe remaining ring(s) may be saturated, partially saturated orunsaturated. Representative examples of heteroaryl include, but are notlimited to, 6-membered ring substituents such as pyridyl, pyrazyl,pyrimidinyl, pyridazinyl; 5-membered ring substituents such as imidazyl,furanyl, thiophenyl, pyrazolyl, oxazolyl, isoxazolyl, thiazolyl, 1,2,3-,1,2,4-, 1,2,5-, or 1,3,4-oxadiazolyl and isothiazolyl; fused ringsubstituents such as benzothiazolyl, benzothiofuranyl, benzisoxazolyl,benzoxazolyl, purinyl; benzopyranyl, quinolinyl, isoquinolinyl,cinnolinyl, quinazolinyl, and benzoxazinyl. Unless otherwise specifiedherein, the heteroaryl groups can be substituted or unsubstituted. Thus,the hydrogen atoms of the heteroaryl groups may be optionallysubstituted by one or more substituents, including, but not limited to,acyl, alkenyl, alkoxy, alkyl, alkynyl, carboxy, haloalkyl, halogen,hydroxy, and hydroxyalkyl.

The term “heteroarylalkyl” means a heteroaryl, as defined herein,appended to the parent molecular moiety through an alkylene group, asdefined herein. Representative examples of heteroarylalkyl include, butare not limited to, fur-3-ylmethyl, 1H-imidazol-2-ylmethyl,1H-imidazol-4-ylmethyl, 1-(pyridin-4-yl)ethyl, pyridin-3-ylmethyl,6-chloropyridin-3-ylmethyl, pyridin-4-ylmethyl,(6-(trifluoromethyl)pyridin-3-yl)methyl, (6-(cyano)pyridin-3-yl)methyl,(2-(cyano)pyridin-4-yl)methyl, (5-(cyano)pyridin-2-yl)methyl,(2-(chloro)pyridin-4-yl)methyl, pyrimidin-5-ylmethyl,2-(pyrimidin-2-yl)propyl, thien-2-ylmethyl, and thien-3-ylmethyl.

The term “heteroatom” means a nitrogen, oxygen, or sulfur atom.

The term “heterocycloalkyl” means a saturated heterocyclyl. Unlessotherwise specified herein, the heterocycloalkyl groups can besubstituted or unsubstituted. Thus, the hydrogen atoms of theheterocycloalkyl groups may be optionally substituted by one or moresubstituents, including, but not limited to, acyl, alkenyl, alkoxy,alkyl, alkynyl, carboxy, haloalkyl, halogen, hydroxy, and hydroxyalkyl.

The term “heterocyclyl” or “heterocyclic” means a saturated, partiallysaturated, or completely unsaturated ring structure containing a totalof 3 to 14 ring atoms, where at least one of the ring atoms is aheteroatom (i.e., oxygen, nitrogen, or sulfur), with the remaining ringatoms being independently selected from the group consisting of carbon,oxygen, nitrogen, and sulfur. A heterocyclic ring may be a single-ring(monocyclic) or polycyclic ring structure. Representative examples ofmonocyclic heterocycles include, but are not limited to, azetidinyl,azepanyl, aziridinyl, diazepanyl, 1,3-dioxanyl, 1,3-dioxolanyl,1,3-dithiolanyl, 1,3-dithianyl, imidazolinyl, imidazolidinyl,isothiazolinyl, isothiazolidinyl, isoxazolinyl, isoxazolidinyl,morpholinyl, oxadiazolinyl, oxadiazolidinyl, oxazolinyl, oxazolidinyl,piperazinyl, piperidinyl, pyranyl, pyrazolinyl, pyrazolidinyl,pyrrolinyl, pyrrolidinyl, tetrahydrofuranyl, tetrahydropyranyl,tetrahydropyridinyl, tetrahydrothienyl, thiadiazolinyl,thiadiazolidinyl, 1,2-thiazinanyl, 1,3-thiazinanyl, thiazolinyl,thiazolidinyl, thiomorpholinyl, 1,1-dioxidothiomorpholinyl(thiomorpholine sulfone), thiopyranyl, and trithianyl.

The term “hydroxyl” or “hydroxy” means an —OH group.

The term “hydroxyalkyl” means at least one hydroxy group, as definedherein, is appended to the parent molecular moiety through an alkylenegroup, as defined herein. Representative examples of hydroxyalkylinclude, but are not limited to, hydroxymethyl, 2-hydroxyethyl,3-hydroxypropyl, 2,3-dihydroxypentyl, and 2-ethyl-4-hydroxyheptyl.

If a particular substituent is described as being “substituted”, itmeans that there are one or more substituents other than hydrogenattached to that particular substituent. Thus, for example, asubstituted alkyl is an alkyl in which at least one non-hydrogensubstituent is in the place of a hydrogen atom on the alkyl. If aparticular substituent is described as being “optionally substituted”,that particular substituent may be either (1) not substituted or (2)substituted.

The terms “treat”, “treating” and “treatment” refer to a method ofalleviating or abrogating a condition, disorder, or disease and/or theattendant symptoms thereof.

The terms “prevent”, “preventing” and “prevention” refer to a method ofpreventing the onset of a condition, disorder, or disease and/or theattendant symptoms thereof or barring a subject from acquiring acondition, disorder, or disease. As used herein, “prevent”, “preventing”and “prevention” also include delaying the onset of a condition,disorder, or disease and/or the attendant symptoms thereof and reducinga subject's risk of acquiring a condition, disorder, or disease.

The term “pharmaceutically acceptable” is used adjectivally to mean thatthe modified noun is appropriate for use as a pharmaceutical product oras a part of a pharmaceutical product.

The term “therapeutically effective amount” means a sufficient amount ofthe compound to treat a condition, disorder, or disease, at a reasonablebenefit/risk ratio applicable to any medical treatment. When used in amedical treatment, a therapeutically effective amount of one of thepresent compounds can be employed in pure form or, where such formsexist, in pharmaceutically acceptable salt or ester, or amide form.Alternatively, the compound can be administered as a pharmaceuticalcomposition containing the compound of interest in combination with oneor more pharmaceutically acceptable carriers.

The term “subject” includes humans and other primates as well asdomesticated and semi-domesticated animals including, but not limitedto, poultry, honeybees, cows, sheep, goats, pigs, horses, dogs, cats,rabbits, rats, mice and the like. The term “poultry” encompasses alltypes of domestic fowl, including, but not limited to chickens, turkey,ducks, geese, the ratite group of birds and game birds. In certainembodiments, the subject is a human.

B. METHODS OF USE

In one aspect, the present invention provides a method of treating adisease caused by a filarial worm infection. In certain embodiments, amacrolide antibiotic is used in human medical therapy, particularly inthe treatment of worm-associated disease. In certain embodiments, amacrolide antibiotic is used in veterinary medical therapy, particularlyin the treatment of worm-associated disease. In certain embodiments, themethod includes administering a therapeutically effective amount of amacrolide antibiotic to a subject having a disease caused by a filarialworm infection. In certain embodiments, the macrolide antibiotic istylosin A, a tylosin A analog, a tylosin A derivative, or a saltthereof. In certain embodiments, the macrolide antibiotic is tylosintartrate (commercially available as Tylan®). In certain embodiments, themacrolide antibiotic is tylvalosin tartrate (commercially available asAivlosin®) or tilmicosin phosphate (commercially available as Micotil®).In certain embodiments, the macrolide antibiotic is tylosin B, or a saltthereof.

In one aspect, the present invention provides a method of treating adisease caused by a filarial worm infection. In certain embodiments, acompound of Formula (I), (I-1), (II), (III), (IV), (V), (VI), (VII),(VIII), (IX), or a pharmaceutically acceptable salt thereof, is used inhuman medical therapy, particularly in the treatment of worm-associateddisease. In certain embodiments, a compound of Formula (I), (I-1), (II),(III), (IV), (V), (VI), (VII), (VIII), (IX), or a pharmaceuticallyacceptable salt thereof, is used in veterinary medical therapy,particularly in the treatment of worm-associated disease. In certainembodiments, the method includes administering a therapeuticallyeffective amount of a compound of Formula (I), (I-1), (II), (III), (IV),(V), (VI), (VII), (VIII), (IX), or a pharmaceutically acceptable saltthereof, to a subject having a disease caused by a filarial worminfection.

In another aspect, the present invention provides a method of preventinga disease caused by a filarial worm infection. In certain embodiments, amacrolide antibiotic is used in human medical therapy, particularly inthe prevention of worm-associated disease. In certain embodiments, amacrolide antibiotic is used in veterinary medical therapy, particularlyin the prevention of worm-associated disease. In certain embodiments,the method includes administering a therapeutically effective amount ofa macrolide antibiotic to a subject to prevent a disease caused by afilarial worm infection. In certain embodiments, the macrolideantibiotic is tylosin A, a tylosin A analog, a tylosin A derivative, ora salt thereof. In certain embodiments, the macrolide antibiotic istylosin tartrate (commercially available as Tylan®). In certainembodiments, the macrolide antibiotic is tylvalosin tartrate(commercially available as Aivlosin®) or tilmicosin phosphate(commercially available as Micotil®).

In another aspect, the present invention provides a method of preventinga disease caused by a filarial worm infection. In certain embodiments, acompound of Formula (I), (I-1), (II), (III), (IV), (V), (VI), (VII),(VIII), (IX), or a pharmaceutically acceptable salt thereof, is used inhuman medical therapy, particularly in the prevention of worm-associateddisease. In certain embodiments, a compound of Formula (I), (I-1), (II),(III), (IV), (V), (VI), (VII), (VIII), (IX), or a pharmaceuticallyacceptable salt thereof, is used in veterinary medical therapy,particularly in the prevention of worm-associated disease. In certainembodiments, the method includes administering a therapeuticallyeffective amount of a compound of Formula (I), (I-1), (II), (III), (IV),(V), (VI), (VII), (VIII), (IX), or a pharmaceutically acceptable saltthereof, to a subject to prevent a disease caused by a filarial worminfection.

In another aspect, the present invention provides a method of preventingor treating a parasitic disease. In certain embodiments, the parasiticdisease is associated with a worm. In certain embodiments, the parasiticdisease is caused by a worm. In certain embodiments, the parasiticdisease is associated with a helminth. In certain embodiments, theparasitic disease is associated with a nematode. In certain embodiments,the nematode is Wuchereria bancrofti. In certain embodiments, thenematode is Brugia malayi. In certain embodiments, the nematode isBrugia timori. In certain embodiments, the nematode is Dirofilariaimmitis. In certain embodiments, the parasitic disease is associatedwith a trematode. In certain embodiments, the parasitic disease isassociated with Schistosoma. In certain embodiments, the parasiticdisease is associated with Schistosoma mansoni. In certain embodiments,the parasitic disease is enterobiasis, oxyuriasis, ascariasis,dracunculiasis, filariasis, onchocerciasis, schistosomiasis, ortrichuriasis. In certain embodiments, the parasitic disease isschistosomiasis. In certain embodiments, the parasitic disease isurinary schistosomiasis. In certain embodiments, the parasitic diseaseis intestinal schistosomiasis. In certain embodiments, the parasiticdisease is Asian intestinal schistosomiasis. In certain embodiments, theparasitic disease is visceral schistosomiasis. In certain embodiments,the parasitic disease is acute schistosomiasis. In certain embodiments,the parasitic disease is lymphatic filariasis. In certain embodiments,the parasitic disease is bancroftian filariasis. In certain embodiments,the parasitic disease is subcutaneous filariasis. In certainembodiments, the parasitic disease is serious cavity filariasis. Incertain embodiments, the parasitic disease is elephantiasis. In certainembodiments, the parasitic disease is elephantiasis tropica. In certainembodiments, the parasitic disease is onchocerciasis.

In certain aspects, the present methods include a step of administeringa macrolide antibiotic, tylosin A, tylosin B, a tylosin A analog, atylosin A derivative, a compound of Formula (I), (I-1), (II), (III),(IV), (V), (VI), (VII), (VIII), (IX), or a pharmaceutically acceptablesalt thereof, to a subject. In certain embodiments, the methods compriseadministering a macrolide antibiotic, tylosin A, tylosin B, a tylosin Aanalog, a tylosin A derivative, a compound of Formula (I), (I-1), (II),(III), (IV), (V), (VI), (VII), (VIII), (IX), or a pharmaceuticallyacceptable salt thereof, to a subject for no more than fourteen (14)days. In certain embodiments, the methods comprise administering amacrolide antibiotic, tylosin A, tylosin B, a tylosin A analog, atylosin A derivative, a compound of Formula (I), (I-1), (II), (III),(IV), (V), (VI), (VII), (VIII), (IX), or a pharmaceutically acceptablesalt thereof, to a subject for no more than seven (7) days. In certainembodiments, the subject is in need of treatment for a fliarialinfection. In certain embodiments, the subject is a pediatric subject.In certain embodiments, the subject is less than nine (9) years of age.In certain embodiments, the subject is less than eight (8) years of age.In certain embodiments, the subject is a pregnant woman. In certainembodiments, the subject is a post-partum woman. In certain embodiments,the subject is a woman of childbearing potential. In certainembodiments, the subject is an individual attempting to conceive achild.

Compounds disclosed herein exhibit potency against filarial worms, and,therefore, have the potential to kill and/or inhibit the growth of suchfilarial worms. Thus, one aspect of the present invention includes amethod of killing a filarial worm, comprising: contacting the filarialworm with tylosin, a tylosin A analog, a tylosin A derivative, acompound of Formula (I), (I-1), (II), (III), (IV), (V), (VI), (VII),(VIII), (IX), or a pharmaceutically acceptable salt thereof, in anamount effective to kill the filarial worm. Another aspect of thepresent invention includes a method of inhibiting growth of a filarialworm, comprising: contacting the filarial worm with tylosin, a tylosin Aanalog, a tylosin A derivative, a compound of Formula (I), (I-1), (II),(III), (IV), (V), (VI), (VII), (VIII), (IX), or a pharmaceuticallyacceptable salt thereof, in an amount effective to inhibit growth of thefilarial worm. In certain embodiments, the worm is an egg. In certainembodiments, the egg is an unfertilized egg. In certain embodiments, theegg is fertilized egg. In certain embodiments, the worm is a larva. Incertain embodiments, the worm is mature. In certain embodiments, theworm is fully mature. In certain embodiments, the worm is contacted withtylosin, a tylosin A analog, a tylosin A derivative, a compound ofFormula (I), (I-1), (II), (III), (IV), (V), (VI), (VII), (VIII), (IX),or a pharmaceutically acceptable salt thereof, inside an animal. Incertain embodiments, the worm is contacted with tylosin, a tylosin Aanalog, a tylosin A derivative, a compound of Formula (I), (I-1), (II),(III), (IV), (V), (VI), (VII), (VIII), (IX), or a pharmaceuticallyacceptable salt thereof, outside an animal.

Compounds disclosed herein exhibit potency against bacteria which areassociated with filarial worms. Thus, one aspect of the presentinvention includes a method of killing bacteria associated with afilarial worm, comprising: contacting the bacteria associated with afilarial worm with tylosin, a tylosin A analog, a tylosin A derivative,a compound of Formula (I), (I-1), (II), (III), (IV), (V), (VI), (VII),(VIII), (IX), or a pharmaceutically acceptable salt thereof, in anamount effective to kill the bacteria. Another aspect of the presentinvention includes a method of inhibiting growth of a bacteriaassociated with a filarial worm, comprising: contacting the bacteriaassociated with a filarial worm with tylosin, a tylosin A analog, atylosin A derivative, a compound of Formula (I), (I-1), (II), (III),(IV), (V), (VI), (VII), (VIII), (IX), or a pharmaceutically acceptablesalt thereof, in an amount effective to inhibit growth of the bacteria.In certain embodiments, the bacteria are contacted with the compound ofFormula I, or the pharmaceutically acceptable salt thereof, inside thefilarial worm. In certain embodiments, the bacteria are contacted withtylosin, a tylosin A analog, a tylosin A derivative, a compound ofFormula (I), (I-1), (II), (III), (IV), (V), (VI), (VII), (VIII), (IX),or a pharmaceutically acceptable salt thereof, outside the filarialworm.

As discussed herein, compounds disclosed herein are useful for treatingand preventing certain diseases and disorders in humans and animals. Incertain embodiments, tylosin, a tylosin A analog, a tylosin Aderivative, a compound of Formula (I), (I-1), (II), (III), (IV), (V),(VI), (VII), (VIII), (IX), or a pharmaceutically acceptable saltthereof, is used to treat disease caused by filarial worm infection,including, but not limited to, heartworm disease, onchocerciasis, andlymphatic filariasis. In certain embodiments, treatment or prevention ofsuch diseases and disorders can be effected by administering tylosin, atylosin A analog, a tylosin A derivative, a compound of Formula (I),(I-1), (II), (III), (IV), (V), (VI), (VII), (VIII), (IX), or apharmaceutically acceptable salt thereof, either alone or in combinationwith another active agent as part of a combination therapy. The term“combination” as in the phrase “in combination with another activeagent” includes co-administration of a first agent and a second agent,which for example may be dissolved or intermixed in the samepharmaceutically acceptable carrier, or administration of a first agent,followed by the second agent, or administration of the second agent,followed by the first agent. The present methods and compositions,therefore, include methods of combination therapeutic treatment andcombination pharmaceutical compositions. The term “combination therapy”refers to the administration of two or more therapeutic substances, suchas a macrolide antibiotic and another drug (e.g., an antihelminthicagent such as ivermectin, albendazole, flubendazole, diethylcarbamazine,or emodepside). The other drug(s) may be administered concomitant with,prior to, or following the administration of the macrolide antibiotic.

The preferred total daily dose of a compound or salt (administered insingle or divided doses) is typically from about 0.001 to about 100mg/kg, more preferably from about 0.001 to about 30 mg/kg, and even morepreferably from about 0.01 to about 10 mg/kg (i.e., mg of the compoundor salt per kg body weight). In certain embodiments, dosage unitcompositions contain such amounts or submultiples thereof to make up thedaily dose. In many instances, the administration of the compound orsalt will be repeated a plurality of times. In certain embodiments,multiple doses per day typically may be used to increase the total dailydose, if desired.

Factors affecting the preferred dosage regimen include the type, age,weight, sex, diet, and condition of the patient; the severity of thepathological condition; the route of administration; pharmacologicalconsiderations, such as the activity, efficacy, pharmacokinetic, andtoxicology profiles of the particular compound or salt used; whether adrug delivery system is utilized; and whether the compound or salt isadministered as part of a drug combination. Thus, the dosage regimenactually employed can vary widely, and therefore, can derive from thepreferred dosage regimen set forth above.

C. COMPOUNDS FOR PREVENTION OR TREATMENT OF FILARIASIS

In certain embodiments, the present methods employ a macrolideantibiotic, including, but not limited to, tylosin A or a salt thereof.

In certain embodiments, the present methods employ tylosin A(2-((4R,5S,6S,7R,9R,11E,13E,15R,16R)-6-(((2R,3R,4R,5S,6R)-5-(((2S,4R,5S,6S)-4,5-dihydroxy-4,6-dimethyltetrahydro-2H-pyran-2-yl)oxy)-4-(dimethylamino)-3-hydroxy-6-methyltetrahydro-2H-pyran-2-yl)oxy)-16-ethyl-4-hydroxy-15-((((2R,3R,4R,5R,6R)-5-hydroxy-3,4-dimethoxy-6-methyltetrahydro-2H-pyran-2-yl)oxy)methyl)-5,9,13-trimethyl-2,10-dioxooxacyclohexadeca-11,13-dien-7-yl)acetaldehyde)or a salt thereof, which is a macrolide antibiotic that is commonly usedto treat veterinary infections. Tylosin A is commercially available as,for example, tylosin tartrate (Tylan®).

In certain embodiments, the present methods employ tylvalosin or a saltthereof. Tylvalosin is commercially available as, for example,tylvalosin tartrate (Aivlosin®).

In certain embodiments, the present methods employ desmycosin, orTylosin B, or a salt thereof.

In certain embodiments, the present methods employ tilmicosin or a saltthereof. Tilmicosin is commercially available as, for example,tilmicosin phosphate (Micotil®).

In certain embodiments, the present methods employ a compound having astructure of Formula (I), (II), (III), (IV), (V), (VI), (VII), or (VIII)or a salt thereof as further defined herein. In various embodiments,there can be variables that occur more than one time in any substituentor in the compound or any other formulae herein. Definition of avariable on each occurrence is independent of its definition at anotheroccurrence. Further, combinations of variables or substituents arepermissible only if such combinations result in stable compounds. Stablecompounds are compounds that can be isolated from a reaction mixture.

In certain embodiments, the present methods employ a compound having astructure of Formula (I):

and salts thereof, wherein:

R₁ represents hydrogen or —C(O)R₃, wherein R₃ represents an optionallysubstituted C₁-C₆-alkyl or C₁-C₆-haloalkyl;

R₂ represents —C(O)C(R₄)(R₅)(R₆), wherein R₄ is selected from the groupconsisting of hydrogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, aryl, heteroaryl,C₃-C₈-cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, andC₃-C₈-cycloalkyl-C₁-C₄-alkyl; and each of R₅ and R₆ are independentlyselected from the group consisting of C₁-C₆-alkyl, C₁-C₆-haloalkyl,aryl, heteroaryl, C₃-C₈-cycloalkyl, heterocycloalkyl, arylalkyl,heteroarylalkyl, and C₃-C₈-cycloalkyl-C₁-C₄-alkyl; or

R₂ represents —C(O)N(R₇)(R₈), wherein each of R₇ and R₈ areindependently selected from the group consisting of hydrogen,C₁-C₆-alkyl, C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl,heterocycloalkyl, arylalkyl, heteroarylalkyl, andC₃-C₈-cycloalkyl-C₁-C₄-alkyl, or R₇ and R₈ together with the nitrogenatom to which they are attached form an optionally substituted saturatedor partially saturated heterocyclic ring; or

R₂ represents —CH₂-A₁, wherein A₁ represents a 6- to 10-membered aryl ora 5- to 10-membered heteroaryl and A₁ is unsubstituted or substitutedwith one or more R_(A), wherein each R_(A) is independently selectedfrom the group consisting of halogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, and—O—R₉, where R₉ represents C₁-C₆-alkyl; and

R₁₀ represents hydrogen or —C(O)R₁₁, wherein R₁₁ represents anoptionally substituted C₁-C₆-alkyl, C₁-C₆-haloalkyl, aryl, heteroaryl,C₃-C₈-cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, orC₃-C₈-cycloalkyl-C₁-C₄-alkyl; and

each of a and b independently represents either a single bond or adouble bond.

In certain embodiments, R₁ is hydrogen.

In certain embodiments, R₁ is —C(O)R₃. In certain embodiments, R₃ isC₁-C₆-alkyl, such as methyl; ethyl; propyl, such as n-propyl orisopropyl; or butyl, such as n-butyl, isobutyl, or tert-butyl.

In certain embodiments, R₂ is —C(O)C(R₄)(R₅)(R₆). In certainembodiments, R₄ is hydrogen. In certain embodiments, each of R₄, R₅, andR₆ are independently selected from the group consisting of C₁-C₆-alkyl,C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl, heterocycloalkyl,arylalkyl, heteroarylalkyl, and C₃-C₈-cycloalkyl-C₁-C₄-alkyl. In certainembodiments, R₄ is C₁-C₆ alkyl. In certain embodiments, R₅ is C₁-C₆alkyl. In certain embodiments, R₆ is C₁-C₆ alkyl. In certainembodiments, each of R₄, R₅, and R₆ are C₁-C₆ alkyl.

In certain embodiments, each of R₄, R₅, and R₆ are C₁-C₆-alkyl. Incertain embodiments, R₄, R₅, and R₆ are the same. For example, incertain embodiments, each of R₄, R₅, and R₆ are methyl. In certainembodiments, at least two of R₄, R₅, and R₆ are the same. In certainembodiments, R₄, R₅, and R₆ are different.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈). In certain embodiments,each of R₇ and R₈ are independently selected from the group consistingof C₁-C₆-alkyl, C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl,heterocycloalkyl, arylalkyl, heteroarylalkyl, andC₃-C₈-cycloalkyl-C₁-C₄-alkyl. In certain embodiments, R₇ and R₈ togetherwith the nitrogen atom to which they are attached form an optionallysubstituted saturated or partially saturated heterocyclic ring. Forinstance R₇ and R₈, taken together with the atoms to which they areattached, can form, without limitation, an optionally substitutedsaturated heterocyclic ring such as

where X is O, S, or N(R_(B)). R_(B) is selected from hydrogen,C₁-C₆-alkyl, C₂-C₆-alkenyl, or C₂-C₆-alkynyl and n is 0, 1, 2, or 3.

In certain embodiments, R₂ is —CH₂-A₁ and A₁is a 6- to 10-membered arylor a 5- to 10-membered heteroaryl. In certain embodiments, A₁ is phenyl,pyrazinyl, pyridinyl, pyrimidinyl, pyridazinyl, oxazolyl, thiazolyl,thienyl, furanyl, imidazolyl, pyrazolyl, triazolyl, benzoxazolyl,benzothienyl, benzimidazolyl, benzofuranyl, benzothiazolyl, indolyl,indenyl, naphthalenyl, quinolinyl, isoquinolinyl, quinoxalinyl,cinnolinyl, quinazolinyl, or phthalazinyl; each of which is optionallysubstituted. In certain embodiments, A₁ is

where Q is O, S, or N(R_(C)). R_(C) is selected from hydrogen,C₁-C₆-alkyl, or C₁-C₆-haloalkyl.

In certain embodiments, A₁is unsubstituted. In certain embodiments, A₁issubstituted with one or more R_(A). In certain embodiments, R_(A) ishalogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, or —O—R₉. In certain embodiments,R_(A) is —O—R₉ and R₉ is C₁-C₆-alkyl. In certain embodiments, R_(A) ishalogen, C₁-C₆-alkyl, or C₁-C₆-haloalkyl.

In certain embodiments, R₁ is —C(O)R₃ and R₃ is C₁-C₆-alkyl. In certainembodiments, R₃ is methyl. In certain embodiments, R₃ is propyl. Incertain embodiments, R₃ is n-propyl. In certain embodiments, R₃ isisopropyl. In certain embodiments, R₃ is butyl. In certain embodiments,R₃ is n-butyl. In certain embodiments, R₃ is isobutyl. In certainembodiments, R₃ is tert-butyl.

In certain embodiments, R₂ is —C(O)C(R₄)(R₅)(R₆) and each of R₄, R₅, andR₆ are C₁-C₆ alkyl. In certain embodiments, R₄ is methyl. In certainembodiments, R₅ is methyl. In certain embodiments, R₆ is methyl. Incertain embodiments, each of R₄, R₅, and R₆ are methyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and one or both of R₇ or R₈are C₁-C₆ alkyl. In certain embodiments, one or both of R₇ or R₈ aremethyl. In certain embodiments, one or both of R₇ or R₈ are ethyl. Incertain embodiments, one or both of R₇ or R₈ are propyl, such asn-propyl or isopropyl. In certain embodiments, one or both of R₇ or R₈are butyl, such as n-butyl, isobutyl, or sec-butyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and each of R₇ and R₈ areC₁-C₆ alkyl. In certain embodiments, both of R₇ and R₈ are methyl. Incertain embodiments, both of R₇ and R₈ are ethyl. In certainembodiments, both of R₇ and R₈ are propyl, such as n-propyl orisopropyl. In certain embodiments, both of R₇ and R₈ are butyl, such asn-butyl, isobutyl, or sec-butyl. In certain embodiments, one of R₇ or R₈is butyl and the other of R₇ or R₈ is ethyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and one or both of R₇ or R₈are C₃-C₈-cycloalkyl. In certain embodiments, both of R₇ and R₈ areC₃-C₈-cycloalkyl. In certain embodiments, both of R₇ and R₈ arecyclohexyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and one of R₇ or R₈ isC₁-C₆ alkyl and the other of R₇ or R₈ is aryl. In certain embodiments,one of R₇ or R₈ is phenyl and the other of R₇ or R₈ is ethyl.

In certain embodiments, R₂ is dialkyl carbamoyl. In certain embodiments,R₂ is dimethyl carbamoyl. In certain embodiments, R₂ is diethylcarbamoyl. In certain embodiments, R₂ is dipropyl carbamoyl. In certainembodiments, R₂ is di(propan-2-yl)carbamoyl. In certain embodiments, R₂is dibutyl carbamoyl. In certain embodiments, R₂ isbis(2-methylpropyl)carbamoyl. In certain embodiments, R₂ isN-butyl-N-ethylcarbamoyl.

In certain embodiments, R₂ is N-methyl-N-phenylcarbamoyl.

In certain embodiments, R₂ is dicyclohexylcarbamoyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and R₇ and R₈ together withthe nitrogen atom to which they are attached form an optionallysubstituted saturated or partially saturated heterocyclic ring. Incertain embodiments, the heterocyclic ring is a non-aromatic ring. Incertain embodiments, the heterocyclic ring is a pyrrolidine. In certainembodiments, the heterocyclic ring is a piperidine. In certainembodiments, the heterocyclic ring is a morpholine. In certainembodiments, the heterocyclic ring is an azepane.

In certain embodiments, R₂ is —CH₂-A₁.

In certain embodiments, A₁ is an unsubstituted phenyl. In certainembodiments, R₂ is unsubstituted benzyl.

In certain embodiments, A₁ is a phenyl substituted with one or moreR_(A). In certain embodiments, R_(A) is haloalkyl. In certainembodiments, R_(A) is trifluoromethyl. In certain embodiments, R_(A) ishalogen. In certain embodiments, R_(A) is fluoro. In certainembodiments, R_(A) is chloro. In certain embodiments, R_(A) is analkoxy, such as methoxy. In certain embodiments, R₂ is substitutedbenzyl. In certain embodiments, R₂ is trifluoromethylbenzyl. In certainembodiments, R₂ is trifluorobenzyl. In certain embodiments, R₂ isfluorobenzyl. In certain embodiments, R₂ is difluorobenzyl. In certainembodiments, R₂ is chlorobenzyl. In certain embodiments, R₂ is4-methoxybenzyl.

In certain embodiments, A₁ is naphthalene. In certain embodiments, A₁ isbenzothiazole.

In certain embodiments, R₁₀ is —C(O)R₁₁. In certain embodiments, R₁₁ isC₁-C₆-alkyl, such as methyl; ethyl; propyl, such as n-propyl orisopropyl; or butyl, such as n-butyl, isobutyl, or tert-butyl. Incertain embodiments, R₁₁ is aryl, such as substituted or unsubstitutedphenyl.

In certain embodiments, R₁₁ is methyl. In certain embodiments, R₁₁₀ isethyl. In certain embodiments, R₁₁ is isopropyl.

In certain embodiments, both a and b are a double bond. In certainembodiments, at least one of a and b are a single bond. In certainembodiments, both a and b are a single bond.

In certain embodiments, both a and b are a double bond; R₁ and R₁₀ areboth hydrogen; and A₁ is neither unsubstituted phenyl nor4-methoxyphenyl.

In certain embodiments, both a and b are a double bond; R₁ and R₁₀ areboth hydrogen or both C(O)CH₃; and neither R₇ nor R₈ is hydrogen.

In certain embodiments, the present methods employ a compound having astructure of Formula (I-1):

and salts thereof, wherein:

R₁ represents hydrogen or —C(O)R₃, wherein R₃ represents C₁-C₆-alkyl;

R₂ represents —C(O)C(R₄)(R₅)(R₆), wherein R₄ is selected from the groupconsisting of hydrogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, aryl, heteroaryl,C₃-C₈-cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, andC₃-C₈-cycloalkyl-C₁-C₄-alkyl; and each of R₅ and R₆ are independentlyselected from the group consisting of C₁-C₆-alkyl, C₁-C₆-haloalkyl,aryl, heteroaryl, C₃-C₈-cycloalkyl, heterocycloalkyl, arylalkyl,heteroarylalkyl, and C₃-C₈-cycloalkyl-C₁-C₄-alkyl; or

R₂ represents —C(O)N(R₇)(R₈), wherein each of R₇ and R₈ areindependently selected from the group consisting of C₁-C₆-alkyl,C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl, heterocycloalkyl,arylalkyl, heteroarylalkyl, and C₃-C₈-cycloalkyl-C₁-C₄-alkyl, or R₇ andR₈ together with the nitrogen atom to which they are attached form anoptionally substituted saturated or partially saturated heterocyclicring; or

R₂ represents —CH₂-A₁, wherein A₁ represents a 6- to 10-membered aryl ora 5- to 10-membered heteroaryl and A₁ is unsubstituted or substitutedwith one or more R_(A), wherein each R_(A) is independently selectedfrom the group consisting of halogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, and—O—R₉, where R₉ represents C₁-C₆-alkyl; and

each of a and b independently represents either a single bond or adouble bond.

In certain embodiments, R₁ is hydrogen.

In certain embodiments, R₁ is —C(O)R₃. In certain embodiments, R₃ isC₁-C₆-alkyl, such as methyl; ethyl; propyl, such as n-propyl orisopropyl; or butyl, such as n-butyl, isobutyl, or tert-butyl.

In certain embodiments, R₂ is —C(O)C(R₄)(R₅)(R₆). In certainembodiments, R₄ is hydrogen. In certain embodiments, each of R₄, R₅, andR₆ are independently selected from the group consisting of C₁-C₆-alkyl,C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl, heterocycloalkyl,arylalkyl, heteroarylalkyl, and C₃-C₈-cycloalkyl-C₁-C₄-alkyl. In certainembodiments, R₄ is C₁-C₆ alkyl. In certain embodiments, R₅ is C₁-C₆alkyl. In certain embodiments, R₆ is C₁-C₆ alkyl. In certainembodiments, each of R₄, R₅, and R₆ are C₁-C₆ alkyl.

In certain embodiments, each of R₄, R₅, and R₆ are C₁-C₆-alkyl. Incertain embodiments, R₄, R₅, and R₆ are the same. For example, incertain embodiments, each of R₄, R₅, and R₆ are methyl. In certainembodiments, at least two of R₄, R₅, and R₆ are the same. In certainembodiments, R₄, R₅, and R₆ are different.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈). In certain embodiments,each of R₇ and R₈ are independently selected from the group consistingof C₁-C₆-alkyl, C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl,heterocycloalkyl, arylalkyl, heteroarylalkyl, andC₃-C₈-cycloalkyl-C₁-C₄-alkyl. In certain embodiments, R₇ and R₈ togetherwith the nitrogen atom to which they are attached form an optionallysubstituted saturated or partially saturated heterocyclic ring. Forinstance R₇ and R₈, taken together with the atoms to which they areattached, can form, without limitation, an optionally substitutedsaturated heterocyclic ring such as

where X is O, S, or N(R_(B)). R_(B) is selected from hydrogen,C₁-C₆-alkyl, C₂-C₆-alkenyl, or C₂-C₆-alkynyl and n is 0, 1, 2, or 3.

In certain embodiments, R₂ is —CH₂-A₁ and A₁ is a 6- to 10-membered arylor a 5- to 10-membered heteroaryl. In certain embodiments, A₁ is phenyl,pyrazinyl, pyridinyl, pyrimidinyl, pyridazinyl, oxazolyl, thiazolyl,thienyl, furanyl, imidazolyl, pyrazolyl, triazolyl, benzoxazolyl,benzothienyl, benzimidazolyl, benzofuranyl, benzothiazolyl, indolyl,indenyl, naphthalenyl, quinolinyl, isoquinolinyl, quinoxalinyl,cinnolinyl, quinazolinyl, or phthalazinyl; each of which is optionallysubstituted. In certain embodiments, A₁ is

where Q is O, S, or N(R_(C)). R_(C) is selected from hydrogen,C₁-C₆-alkyl, or C₁-C₆-haloalkyl.

In certain embodiments, A₁ is unsubstituted. In certain embodiments, A₁is substituted with one or more R_(A). In certain embodiments, R_(A) ishalogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, or —O—R₉. In certain embodiments,R_(A) is —O—R₉ and R₉ is C₁-C₆-alkyl. In certain embodiments, R_(A) ishalogen, C₁-C₆-alkyl, or C₁-C₆-haloalkyl.

In certain embodiments, R₁ is —C(O)R₃ and R₃ is C₁-C₆-alkyl. In certainembodiments, R₃ is methyl. In certain embodiments, R₃ is propyl. Incertain embodiments, R₃ is n-propyl. In certain embodiments, R₃ isisopropyl. In certain embodiments, R₃ is butyl. In certain embodiments,R₃ is n-butyl. In certain embodiments, R₃ is isobutyl. In certainembodiments, R₃ is tert-butyl.

In certain embodiments, R₂ is —C(O)C(R₄)(R₅)(R₆) and each of R₄, R₅, andR₆ are C₁-C₆ alkyl. In certain embodiments, R₄ is methyl. In certainembodiments, R₅ is methyl. In certain embodiments, R₆ is methyl. Incertain embodiments, each of R₄, R₅, and R₆ are methyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and one or both of R₇ or R₈are C₁-C₆ alkyl. In certain embodiments, one or both of R₇ or R₈ aremethyl. In certain embodiments, one or both of R₇ or R₈ are ethyl. Incertain embodiments, one or both of R₇ or R₈ are propyl, such asn-propyl or isopropyl. In certain embodiments, one or both of R₇ or R₈are butyl, such as n-butyl, isobutyl, or sec-butyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and each of R₇ and R₈ areC₁-C₆ alkyl. In certain embodiments, both of R₇ and R₈ are methyl. Incertain embodiments, both of R₇ and R₈ are ethyl. In certainembodiments, both of R₇ and R₈ are propyl, such as n-propyl orisopropyl. In certain embodiments, both of R₇ and R₈ are butyl, such asn-butyl, isobutyl, or sec-butyl. In certain embodiments, one of R₇ or R₈is butyl and the other of R₇ or R₈ is ethyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and one or both of R₇ or R₈are C₃-C₈-cycloalkyl. In certain embodiments, both of R₇ and R₈ areC₃-C₈-cycloalkyl. In certain embodiments, both of R₇ and R₈ arecyclohexyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and one of R₇ or R₈ isC₁-C₆ alkyl and the other of R₇ or R₈ is aryl. In certain embodiments,one of R₇ or R₈ is phenyl and the other of R₇ or R₈ is ethyl.

In certain embodiments, R₂ is dialkyl carbamoyl. In certain embodiments,R₂ is dimethyl carbamoyl. In certain embodiments, R₂ is diethylcarbamoyl. In certain embodiments, R₂ is dipropyl carbamoyl. In certainembodiments, R₂ is di(propan-2-yl)carbamoyl. In certain embodiments, R₂is dibutyl carbamoyl. In certain embodiments, R₂ isbis(2-methylpropyl)carbamoyl. In certain embodiments, R₂ isN-butyl-N-ethylcarbamoyl.

In certain embodiments, R₂ is N-methyl-N-phenylcarbamoyl.

In certain embodiments, R₂ is dicyclohexylcarbamoyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and R₇ and R₈ together withthe nitrogen atom to which they are attached form an optionallysubstituted saturated or partially saturated heterocyclic ring. Incertain embodiments, the heterocyclic ring is a non-aromatic ring. Incertain embodiments, the heterocyclic ring is a pyrrolidine. In certainembodiments, the heterocyclic ring is a piperidine. In certainembodiments, the heterocyclic ring is a morpholine. In certainembodiments, the heterocyclic ring is an azepane.

In certain embodiments, R₂ is —CH₂-A₁.

In certain embodiments, A₁ is an unsubstituted phenyl. In certainembodiments, R₂ is unsubstituted benzyl.

In certain embodiments, A₁ is a phenyl substituted with one or moreR_(A). In certain embodiments, R_(A) is haloalkyl. In certainembodiments, R_(A) is trifluoromethyl. In certain embodiments, R_(A) ishalogen. In certain embodiments, R_(A) is fluoro. In certainembodiments, R_(A) is chloro. In certain embodiments, R_(A) is analkoxy, such as methoxy. In certain embodiments, R₂ is substitutedbenzyl. In certain embodiments, R₂ is trifluoromethylbenzyl. In certainembodiments, R₂ is trifluorobenzyl. In certain embodiments, R₂ isfluorobenzyl. In certain embodiments, R₂ is difluorobenzyl. In certainembodiments, R₂ is chlorobenzyl. In certain embodiments, R₂ is4-methoxybenzyl.

In certain embodiments, A₁ is naphthalene. In certain embodiments, A₁ isbenzothiazole.

In certain embodiments, both a and b are a double bond. In certainembodiments, at least one of a and b are a single bond. In certainembodiments, both a and b are a single bond.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is benzyl.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is trifluoromethylbenzyl.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is fluorobenzyl.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is chlorobenzyl.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is benzyl.

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is difluorobenzyl.

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ isCH₂-benzothiazolyl.

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is fluorobenzyl.

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is CH₂-naphthalenyl.

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is

In certain embodiments, R₁ is hydrogen and R₂ is fluorobenzyl.

In certain embodiments, R₁ is hydrogen and R₂ is

In certain embodiments, R₁ is —C(O)(CH₂)₃CH₃ and R₂ is fluorobenzyl.

In certain embodiments, R₁ is —C(O)(CH₂)₃CH₃ and R₂ is

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is —C(O)C(CH₃)₃.

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is —C(O)C(CH₃)₃.

In certain embodiments, R₁ is hydrogen and R₂ is —C(O)C(CH₃)₃.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is —C(O)N(CH₂CH₃)₂.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ isN-methyl-N-phenylcarbamoyl.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is —C(O)N(CH₃)(C₆H₅).

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is —C(O)-pyrrolidinyl.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is —C(O)N(CH₂CH₃)₂.

In certain embodiments, R₁ is hydrogen and R₂ is —C(O)N(CH₂CH₃)₂.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is —C(O)-piperidinyl.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is —C(O)-morpholinyl.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is —C(O)N(CH(CH₃)₂)₂.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is —C(O)N((CH₂)₃CH₃)₂.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is —C(O)N(CH₂CH(CH₃)₂)₂.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is —C(O)-azepane.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is dicyclohexylcarbamoyl.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is —C(O)N(CH₃)₂.

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ isN-butyl-N-ethylcarbamoyl.

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is—C(O)N(CH₂CH₃)((CH₂)₃CH₃).

In certain embodiments, R₁ is hydrogen and R₂ is —C(O)N(CH(CH₃)₂)₂.

In certain embodiments, R₁ is hydrogen and R₂ is —C(O)N((CH₂)₃CH₃)₂.

In certain embodiments, R₁ is hydrogen and R₂ is dicyclohexylcarbamoyl.

In certain embodiments, R₁ is H and R₂ is

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is —C(O)-morpholinyl.

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is difluorobenzyl.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is

In certain embodiments, R₁ is —C(O)(CH₂)₃(CH₃) and R₂ is—C(O)-morpholinyl.

In certain embodiments, R₁ is —C(O)(CH₂)₃(CH₃) and R₂ is

In certain embodiments, R₁ is —C(O)(CH₂)₃(CH₃) and R₂ is difluorobenzyl.

In certain embodiments, R₁ is —C(O)(CH₂)₃(CH₃) and R₂ is

In certain embodiments, R₁ is hydrogen and R₂ is —C(O)-morpholinyl.

In certain embodiments, R₁ is hydrogen and R₂ is

In certain embodiments, R₁ is hydrogen and R₂ is difluorobenzyl.

In certain embodiments, R₁ is hydrogen and R₂ is

In certain embodiments, R₁ is hydrogen and R₂ is benzyl.

In certain embodiments, R₁ is hydrogen and R₂ is

In certain embodiments, R₁ is hydrogen and R₂ is methoxybenzyl.

In certain embodiments, R₁ is hydrogen and R₂ is

In one aspect, the present methods employ a compound of Formula (II):

and salts thereof, wherein R₁ and R₂ are as defined above.

In particular, R₁ represents hydrogen or —C(O)R₃, wherein R₃ representsC₁-C₆-alkyl; and

R₂ represents —C(O)C(R₄)(R₅)(R₆), wherein R₄ is selected from the groupconsisting of hydrogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, aryl, heteroaryl,C₃-C₈-cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, andC₃-C₈-cycloalkyl-C₁-C₄-alkyl; and each of R₅ and R₆ are independentlyselected from the group consisting of C₁-C₆-alkyl, C₁-C₆-haloalkyl,aryl, heteroaryl, C₃-C₈-cycloalkyl, heterocycloalkyl, arylalkyl,heteroarylalkyl, and C₃-C₈-cycloalkyl-C₁-C₄-alkyl; or

R₂ represents —C(O)N(R₇)(R₈), wherein each of R₇ and R₈ areindependently selected from the group consisting of C₁-C₆-alkyl,C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl, heterocycloalkyl,arylalkyl, heteroarylalkyl, and C₃-C₈-cycloalkyl-C₁-C₄-alkyl, or R₇ andR₈ together with the nitrogen atom to which they are attached form anoptionally substituted saturated or partially saturated heterocyclicring; or

R₂ represents —CH₂-A₁, wherein A₁ represents a 6- to 10-membered aryl ora 5- to 10-membered heteroaryl and A₁ is unsubstituted or substitutedwith one or more R_(A), wherein each R_(A) is independently selectedfrom the group consisting of halogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, and—O—R₉, where R₉ represents C₁-C₆-alkyl.

In certain embodiments, R₁ is hydrogen.

In certain embodiments, R₁ is —C(O)R₃. In certain embodiments, R₃ isC₁-C₆-alkyl, such as methyl; ethyl; propyl, such as n-propyl orisopropyl; or butyl, such as n-butyl, isobutyl, or tert-butyl.

In certain embodiments, R₂ is —C(O)C(R₄)(R₅)(R₆). In certainembodiments, R₄ is hydrogen. In certain embodiments, each of R₄, R₅, andR₆ are independently selected from the group consisting of C₁-C₆-alkyl,C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl, heterocycloalkyl,arylalkyl, heteroarylalkyl, and C₃-C₈-cycloalkyl-C₁-C₄-alkyl. In certainembodiments, R₄ is C₁-C₆ alkyl. In certain embodiments, R₅ is C₁-C₆alkyl. In certain embodiments, R₆ is C₁-C₆ alkyl. In certainembodiments, each of R₄, R₅, and R₆ are C₁-C₆ alkyl.

In certain embodiments, each of R₄, R₅, and R₆ are C₁-C₆-alkyl. Incertain embodiments, R₄, R₅, and R₆ are the same. For example, incertain embodiments, each of R₄, R₅, and R₆ are methyl. In certainembodiments, at least two of R₄, R₅, and R₆ are the same. In certainembodiments, R₄, R₅, and R₆ are different.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈). In certain embodiments,each of R₇ and R₈ are independently selected from the group consistingof C₁-C₆-alkyl, C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl,heterocycloalkyl, arylalkyl, heteroarylalkyl, andC₃-C₈-cycloalkyl-C₁-C₄-alkyl. In certain embodiments, R₇ and R₈ togetherwith the nitrogen atom to which they are attached form an optionallysubstituted saturated or partially saturated heterocyclic ring. Forinstance R₇ and R₈, taken together with the atoms to which they areattached, can form, without limitation, an optionally substitutedsaturated heterocyclic ring such as

where X is O, S, or N(R_(B)). R_(B) is selected from hydrogen,C₁-C₆-alkyl, C₂-C₆-alkenyl, or C₂-C₆-alkynyl and n is 0, 1, 2, or 3.

In certain embodiments, R₂ is —CH₂-A₁ and A₁ is a 6- to 10-membered arylor a 5- to 10-membered heteroaryl. In certain embodiments, A₁ is phenyl,pyrazinyl, pyridinyl, pyrimidinyl, pyridazinyl, oxazolyl, thiazolyl,thienyl, furanyl, imidazolyl, pyrazolyl, triazolyl, benzoxazolyl,benzothienyl, benzimidazolyl, benzofuranyl, benzothiazolyl, indolyl,indenyl, naphthalenyl, quinolinyl, isoquinolinyl, quinoxalinyl,cinnolinyl, quinazolinyl, or phthalazinyl; each of which is optionallysubstituted. In certain embodiments, A₁ is

where Q is O, S, or N(R_(C)). R_(C) is selected from hydrogen,C₁-C₆-alkyl, or C₁-C₆-haloalkyl.

In certain embodiments, A₁ is unsubstituted. In certain embodiments, A₁is substituted with one or more R_(A). R_(A) is independently selectedat each occurrence from the group consisting of halogen, C₁-C₆-alkyl,C₁-C₆-haloalkyl, and —O—R₉, where R₉ represents C₁-C₆-alkyl. In certainembodiments, R_(A) is independently selected at each occurrence from thegroup consisting of halogen, C₁-C₆-alkyl, and C₁-C₆-haloalkyl. Incertain embodiments, R_(A) is halogen. In certain embodiments, R_(A) isfluoro. In certain embodiments, R_(A) is chloro. In certain embodiments,R_(A) is —O—R₉. In certain embodiments, R_(A) is —O—R₉ and R₉ is methyl.In certain embodiments, R_(A) is an alkoxy, such as methoxy.

In certain embodiments, R₁ is —C(O)R₃ and R₃ is C₁-C₆-alkyl. In certainembodiments, R₃ is methyl. In certain embodiments, R₃ is propyl. Incertain embodiments, R₃ is n-propyl. In certain embodiments, R₃ isisopropyl. In certain embodiments, R₃ is butyl. In certain embodiments,R₃ is n-butyl. In certain embodiments, R₃ is isobutyl. In certainembodiments, R₃ is tert-butyl.

In certain embodiments, R₂ is —C(O)C(R₄)(R₅)(R₆) and each of R₄, R₅, andR₆ are C₁-C₆ alkyl. In certain embodiments, R₄ is methyl. In certainembodiments, R₅ is methyl. In certain embodiments, R₆ is methyl. Incertain embodiments, each of R₄, R₅, and R₆ are methyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and one or both of R₇ or R₈are C₁-C₆ alkyl. In certain embodiments, one or both of R₇ or R₈ aremethyl. In certain embodiments, one or both of R₇ or R₈ are ethyl. Incertain embodiments, one or both of R₇ or R₈ are propyl, such asn-propyl or isopropyl. In certain embodiments, one or both of R₇ or R₈are butyl, such as n-butyl, isobutyl, or sec-butyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and each of R₇ and R₈ areC₁-C₆ alkyl. In certain embodiments, both of R₇ and R₈ are methyl. Incertain embodiments, both of R₇ and R₈ are ethyl. In certainembodiments, both of R₇ and R₈ are propyl, such as n-propyl orisopropyl. In certain embodiments, both of R₇ and R₈ are butyl, such asn-butyl, isobutyl, or sec-butyl. In certain embodiments, one of R₇ or R₈is butyl and the other of R₇ or R₈ is ethyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and one or both of R₇ or R₈are C₃-C₈-cycloalkyl. In certain embodiments, both of R₇ and R₈ areC₃-C₈-cycloalkyl. In certain embodiments, both of R₇ and R₈ arecyclohexyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and one of R₇ or R₈ isC₁-C₆ alkyl and the other of R₇ or R₈ is aryl. In certain embodiments,one of R₇ or R₈ is phenyl and the other of R₇ or R₈ is ethyl. In certainembodiments, R₁ is —C(O)CH₃ and R₂ is benzyl.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is trifluoromethylbenzyl.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is fluorobenzyl.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is chlorobenzyl.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is benzyl.

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is difluorobenzyl.

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ isCH₂-benzothiazolyl.

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is fluorobenzyl.

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is CH₂-naphthalenyl.

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is

In certain embodiments, R₁ is hydrogen and R₂ is fluorobenzyl.

In certain embodiments, R₁ is hydrogen and R₂ is

In certain embodiments, R₁ is —C(O)(CH₂)₃CH₃ and R₂ is fluorobenzyl.

In certain embodiments, R₁ is —C(O)(CH₂)₃CH₃ and R₂ is

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is —C(O)C(CH₃)₃.

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is —C(O)C(CH₃)₃.

In certain embodiments, R₁ is hydrogen and R₂ is —C(O)C(CH₃)₃.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is —C(O)N(CH₂CH₃)₂.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ isN-methyl-N-phenylcarbamoyl.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is —C(O)N(CH₃)(C₆H₅).

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is —C(O)-pyrrolidinyl.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is —C(O)N(CH₂CH₃)₂.

In certain embodiments, R₁ is hydrogen and R₂ is —C(O)N(CH₂CH₃)₂.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is —C(O)-piperidinyl.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is —C(O)-morpholinyl.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is —C(O)N(CH(CH₃)₂)₂.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is —C(O)N((CH₂)₃CH₃)₂.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is —C(O)N(CH₂CH(CH₃)₂)₂.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is —C(O)-azepane.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is dicyclohexylcarbamoyl.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is —C(O)N(CH₃)₂.

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ isN-butyl-N-ethylcarbamoyl.

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is—C(O)N(CH₂CH₃)((CH₂)₃CH₃).

In certain embodiments, R₁ is hydrogen and R₂ is —C(O)N(CH(CH₃)₂)₂.

In certain embodiments, R₁ is hydrogen and R₂ is —C(O)N((CH₂)₃CH₃)₂.

In certain embodiments, R₁ is hydrogen and R₂ is dicyclohexylcarbamoyl.

In certain embodiments, R₁ is H and R₂ is

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is —C(O)-morpholinyl.

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is difluorobenzyl.

In certain embodiments, R₁ is —C(O)CH₃ and R₂ is

In certain embodiments, R₁ is —C(O)(CH₂)₃(CH₃) and R₂ is—C(O)-morpholinyl.

In certain embodiments, R₁ is —C(O)(CH₂)₃(CH₃) and R₂ is

In certain embodiments, R₁ is —C(O)(CH₂)₃(CH₃) and R₂ is difluorobenzyl.

In certain embodiments, R₁ is —C(O)(CH₂)₃(CH₃) and R₂ is

In certain embodiments, R₁ is hydrogen and R₂ is —C(O)-morpholinyl.

In certain embodiments, R₁ is hydrogen and R₂ is

In certain embodiments, R₁ is hydrogen and R₂ is difluorobenzyl.

In certain embodiments, R₁ is hydrogen and R₂ is

In certain embodiments, R₁ is hydrogen and R₂ is benzyl.

In certain embodiments, R₁ is hydrogen and R₂ is

In certain embodiments, R₁ is hydrogen and R₂ is methoxybenzyl.

In certain embodiments, R₁ is hydrogen and R₂ is

In certain embodiments, a compound of Formula (II) is synthesized asdescribed herein. For example, a compound of Formula (II) can besynthesized as described in the Schemes or Examples described herein. Incertain other embodiments, a compound of Formula (II) is generated invivo following administration of a suitable prodrug. In certainembodiments, a suitable prodrug may include a 4′″-O-acyl moiety (e.g., a4′″-O-acetyl, 4′″-O-propionyl, or 4′″-O-methylpropionyl moiety.

In one aspect, the present methods employ a compound of Formula (III):

and salts thereof, wherein:

R₁ represents hydrogen or —C(O)R₃, where R₃ represents C₁-C₆-alkyl;

A₁ represents a 6- to 10-membered aryl or a 5- to 10-membered heteroaryland A₁ is unsubstituted or substituted with one or more R_(A), whereineach R_(A) is independently selected from the group consisting ofhalogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, and —O—R₉, where R₉ representsC₁-C₆-alkyl; and

each of a and b independently represents either a single bond or adouble bond.

In certain embodiments, R₁ is hydrogen.

In certain embodiments, R₁ is —C(O)R₃. In certain embodiments, R₃ isC₁-C₆-alkyl, such as methyl; ethyl; propyl, such as n-propyl orisopropyl; or butyl, such as n-butyl, isobutyl, or tert-butyl.

In certain embodiments, A₁ is a phenyl substituted with one or moreR_(A). In certain embodiments, R_(A) is halogen. In certain embodiments,A₁ is a halophenyl or a dihalophenyl. In certain embodiments, A₁ is a 7-to 10-membered aryl optionally substituted with one or more R_(A). Incertain embodiments, A₁ is a 5- to 10-membered heteroaryl optionallysubstituted with one or more R_(A). In certain embodiments, each R_(A)independently is selected from the group consisting of halogen,C₁-C₆-alkyl, and C₁-C₆-haloalkyl. In certain embodiments, A₁ issubstituted phenyl or an optionally substituted pyrazinyl, pyridinyl,pyrimidinyl, pyridazinyl, oxazolyl, thiazolyl, thienyl, furanyl,imidazolyl, pyrazolyl, triazolyl, benzoxazolyl, benzothienyl,benzimidazolyl, benzofuranyl, benzothiazolyl, indolyl, indenyl,naphthalenyl, quinolinyl, isoquinolinyl, quinoxalinyl, cinnolinyl,quinazolinyl, or phthalazinyl; each of which is optionally substituted.In certain embodiments, A₁ is

where Q is O, S, or N(R_(C)). R_(C) is selected from hydrogen,C₁-C₆-alkyl, or C₁-C₆-haloalkyl.

In certain embodiments, A₁ is substituted with one or more R_(A). R_(A)is independently selected at each occurrence from the group consistingof halogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, and —O—R₉, where R₉ representsC₁-C₆-alkyl. In certain embodiments, R_(A) is independently selected ateach occurrence from the group consisting of halogen, C₁-C₆-alkyl, andC₁-C₆-haloalkyl. In certain embodiments, R_(A) is halogen. In certainembodiments, R_(A) is fluoro. In certain embodiments, R_(A) is chloro.In certain embodiments, R_(A) is —O—R₉. In certain embodiments, R_(A) is—O—R₉ and R₉ is methyl.

In certain embodiments, A₁ is unsubstituted phenyl. In certainembodiments, A₁ is a phenyl substituted with one or more R_(A). Incertain embodiments, R_(A) is haloalkyl. In certain embodiments, R_(A)is trifluoromethyl. In certain embodiments, R_(A) is halogen. In certainembodiments, R_(A) is fluoro. In certain embodiments, R_(A) is chloro.In certain embodiments, R_(A) is an alkoxy, such as methoxy. In certainembodiments, A₁ is fluorophenyl. In certain embodiments, A₁ ischlorophenyl. In certain embodiments, A₁ is 4-methoxyphenyl.

In certain embodiments, A₁ is a phenyl substituted with two or moreR_(A). In certain embodiments, each of the two or more R_(A) is halogen.In certain embodiments, each of the two or more R_(A) is fluoro. Incertain embodiments, each of the two or more R_(A) is chloro. In certainembodiments, A₁ is dihalophenyl. In certain embodiments, A₁ isdifluorophenyl. In certain embodiments, A₁ is dichlorophenyl.

In certain embodiments, A₁ is a 7- to 10-membered aryl optionallysubstituted with one or more R_(A). In certain embodiments, A₁ isnaphthalene.

In certain embodiments, A₁ is a 5- to 10-membered heteroaryl optionallysubstituted with one or more R_(A). In certain embodiments, A₁ isbenzothiazole.

In certain embodiments, both a and b are a double bond. In certainembodiments, at least one of a and b are a single bond. In certainembodiments, both a and b are a single bond.

In one aspect, the present methods employ a compound of Formula (IV):

and salts thereof, wherein:

R₁ represents hydrogen or —C(O)R₃, where R₃ represents C₁-C₆-alkyl;

R₄ is selected from the group consisting of hydrogen, C₁-C₆-alkyl,C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl, heterocycloalkyl,arylalkyl, heteroarylalkyl, and C₃-C₈-cycloalkyl-C₁-C₄-alkyl;

each of R₅ and R₆ are independently selected from the group consistingof C₁-C₆-alkyl, C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl,heterocycloalkyl, arylalkyl, heteroarylalkyl, andC₃-C₈-cycloalkyl-C₁-C₄-alkyl; and

each of a and b independently represents either a single bond or adouble bond.

In certain embodiments, R₁ is hydrogen.

In certain embodiments, R₁ is —C(O)R₃. In certain embodiments, R₃ isC₁-C₆-alkyl, such as methyl; ethyl; propyl, such as n-propyl orisopropyl; or butyl, such as n-butyl, isobutyl, or tert-butyl.

In certain embodiments, R₄ is hydrogen.

In certain embodiments, each of R₄, R₅, and R₆ are independentlyselected from the group consisting of C₁-C₆-alkyl, C₁-C₆-haloalkyl,aryl, heteroaryl, C₃-C₈-cycloalkyl, heterocycloalkyl, arylalkyl,heteroarylalkyl, and C₃-C₈-cycloalkyl-C₁-C₄-alkyl. In certainembodiments, R₄ is C₁-C₆ alkyl. In certain embodiments, R₄ is methyl. Incertain embodiments, R₅ is C₁-C₆ alkyl. In certain embodiments, R₅ ismethyl. In certain embodiments, R₆ is C₁-C₆ alkyl. In certainembodiments, R₆ is methyl. In certain embodiments, each of R₄, R₅, andR₆ are C₁-C₆ alkyl.

In certain embodiments, R₄, R₅, and R₆ are the same. For example, incertain embodiments, each of R₄, R₅, and R₆ are methyl. In certainembodiments, at least two of R₄, R₅, and R₆ are the same. In certainembodiments, R₄, R₅, and R₆ are different.

In certain embodiments, both a and b are a double bond. In certainembodiments, at least one of a and b are a single bond. In certainembodiments, both a and b are a single bond.

In one aspect, the present methods employ a compound of Formula (V):

and salts thereof, wherein:

R₁ represents hydrogen or —C(O)R₃, where R₃ represents C₁-C₆-alkyl;

each of R₇ and R₈ are independently selected from the group consistingof C₁-C₆-alkyl, C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl,heterocycloalkyl, arylalkyl, heteroarylalkyl, andC₃-C₈-cycloalkyl-C₁-C₄-alkyl, or R₇ and R₈ together with the nitrogenatom to which they are attached form an optionally substituted saturatedor partially saturated heterocyclic ring; and

each of a and b independently represents either a single bond or adouble bond.

In certain embodiments, R₁ is hydrogen.

In certain embodiments, R₁ is —C(O)R₃. In certain embodiments, R₃ isC₁-C₆-alkyl, such as methyl; ethyl; propyl, such as n-propyl orisopropyl; or butyl, such as n-butyl, isobutyl, or tert-butyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈). In certain embodiments,each of R₇ and R₈ are independently selected from the group consistingof C₁-C₆-alkyl, C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl,heterocycloalkyl, arylalkyl, heteroarylalkyl, andC₃-C₈-cycloalkyl-C₁-C₄-alkyl. In certain embodiments, R₇ and R₈ togetherwith the nitrogen atom to which they are attached form an optionallysubstituted saturated or partially saturated heterocyclic ring. Forinstance R₇ and R₈, taken together with the atoms to which they areattached, can form, without limitation, an optionally substitutedsaturated heterocyclic ring such as

where X is O, S, or N(R_(B)). R_(B) is selected from hydrogen,C₁-C₆-alkyl, C₂-C₆-alkenyl, or C₂-C₆-alkynyl and n is 0, 1, 2, or 3.

In certain embodiments, R₁ is —C(O)R₃. In certain embodiments, R₃ ismethyl. In certain embodiments, R₃ is propyl. In certain embodiments, R₃is n-propyl. In certain embodiments, R₃ is isopropyl. In certainembodiments, R₃ is butyl. In certain embodiments, R₃ is n-butyl. Incertain embodiments, R₃ is isobutyl. In certain embodiments, R₃ istert-butyl.

In certain embodiments, one or both of R₇ or R₈ are C₁-C₆ alkyl. Incertain embodiments, one or both of R₇ or R₈ are methyl. In certainembodiments, one or both of R₇ or R₈ are ethyl. In certain embodiments,one or both of R₇ or R₈ are propyl, such as n-propyl or isopropyl. Incertain embodiments, one or both of R₇ or R₈ are butyl, such as n-butyl,isobutyl, or sec-butyl.

In certain embodiments, both of R₇ and R₈ are C₁-C₆ alkyl. In certainembodiments, both of R₇ and R₈ are methyl. In certain embodiments, bothof R₇ and R₈ are ethyl. In certain embodiments, both of R₇ and R₈ arepropyl, such as n-propyl or isopropyl. In certain embodiments, both ofR₇ and R₈ are butyl, such as n-butyl, isobutyl, or sec-butyl. In certainembodiments, one of R₇ or R₈ is butyl and the other of R₇ or R₈ isethyl.

In certain embodiments, one or both of R₇ or R₈ are C₃-C₈-cycloalkyl. Incertain embodiments, both of R₇ and R₈ are C₃-C₈-cycloalkyl. In certainembodiments, both of R₇ and R₈ are cyclohexyl.

In certain embodiments, one or both of R₇ or R₈ are aryl. In certainembodiments, one or both of R₇ or R₈ are phenyl. In certain embodiments,one or both of R₇ or R₈ are unsubstituted phenyl.

In certain embodiments, one of R₇ or R₈ is C₁-C₆ alkyl and the other ofR₇ or R₈ is aryl. In certain embodiments, one of R₇ or R₈ is phenyl andthe other of R₇ or R₈ is methyl or ethyl. In certain embodiments, one ofR₇ or R₈ is unsubstituted phenyl and the other of R₇ or R₈ is methyl.

In certain embodiments, R₇ and R₈ together with the nitrogen atom towhich they are attached form an optionally substituted saturated orpartially saturated heterocyclic ring. In certain embodiments, theheterocyclic ring is a non-aromatic ring. In certain embodiments, theheterocyclic ring is a pyrrolidine. In certain embodiments, theheterocyclic ring is a piperidine. In certain embodiments, theheterocyclic ring is a morpholine. In certain embodiments, theheterocyclic ring is an azepane.

In certain embodiments, both a and b are a double bond. In certainembodiments, at least one of a and b are a single bond. In certainembodiments, both a and b are a single bond.

In one aspect, the present methods employ a compound of Formula (VI):

and salts thereof, wherein:

R₃ represents C₁-C₆-alkyl;

R₂ represents —C(O)C(R₄)(R₅)(R₆), wherein each of R₄, R₅, and R₆ areindependently selected from the group consisting of hydrogen,C₁-C₆-alkyl, C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl,heterocycloalkyl, arylalkyl, heteroarylalkyl, andC₃-C₈-cycloalkyl-C₁-C₄-alkyl; or

R₂ represents —C(O)N(R₇)(R₈), wherein each of R₇ and R₈ areindependently selected from the group consisting of C₁-C₆-alkyl,C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl, heterocycloalkyl,arylalkyl, heteroarylalkyl, and C₃-C₈-cycloalkyl-C₁-C₄-alkyl, or R₇ andR₈ together with the nitrogen atom to which they are attached form anoptionally substituted saturated or partially saturated heterocyclicring; or

R₂ represents —CH₂-A₁, wherein A₁ represents a 6- to 10-membered aryl ora 5- to 10-membered heteroaryl and A₁ is unsubstituted or substitutedwith one or more R_(A), wherein each R_(A) is independently selectedfrom the group consisting of halogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, and—O—R₉, where R₉ represents C₁-C₆-alkyl; and

each of a and b independently represents either a single bond or adouble bond.

In certain embodiments, R₃ is methyl. In certain embodiments, R₃ isethyl. In certain embodiments, R₃ is propyl, such as isopropyl. Incertain embodiments, R₃ is butyl, such as n-butyl.

In certain embodiments, R₂ is —C(O)C(R₄)(R₅)(R₆). Each of R₄, R₅, and R₆are independently selected from the group consisting of hydrogen,C₁-C₆-alkyl, C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl,heterocycloalkyl, arylalkyl, heteroarylalkyl, andC₃-C₈-cycloalkyl-C₁-C₄-alkyl. In certain embodiments, R₄ is C₁-C₆ alkyl.In certain embodiments, R₅ is C₁-C₆ alkyl. In certain embodiments, R₆ isC₁-C₆ alkyl. In certain embodiments, each of R₄, R₅, and R₆ are C₁-C₆alkyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈). In certain embodiments,each of R₇ and R₈ are independently selected from the group consistingof C₁-C₆-alkyl, C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl,heterocycloalkyl, arylalkyl, heteroarylalkyl, andC₃-C₈-cycloalkyl-C₁-C₄-alkyl. In certain embodiments, R₇ and R₈ togetherwith the nitrogen atom to which they are attached form an optionallysubstituted saturated or partially saturated heterocyclic ring. Forinstance R₇ and R₈, taken together with the atoms to which they areattached, can form, without limitation, an optionally substitutedsaturated heterocyclic ring such as

where X is O, S, or N(R_(B)). R_(B) is selected from hydrogen,C₁-C₆-alkyl, C₂-C₆-alkenyl, or C₂-C₆-alkynyl and n is 0, 1, 2, or 3.

In certain embodiments, R₂ is —CH₂-A₁. A₁ is a 6- to 10-membered aryl ora 5- to 10-membered heteroaryl. In certain embodiments, A₁ is phenyl,pyrazinyl, pyridinyl, pyrimidinyl, pyridazinyl, oxazolyl, thiazolyl,thienyl, furanyl, imidazolyl, pyrazolyl, triazolyl, benzoxazolyl,benzothienyl, benzimidazolyl, benzofuranyl, benzothiazolyl, indolyl,indenyl, naphthalenyl, quinolinyl, isoquinolinyl, quinoxalinyl,cinnolinyl, quinazolinyl, or phthalazinyl; each of which is optionallysubstituted. In certain embodiments, A₁ is

where Q is O, S, or N(R_(C)). R_(C) is selected from hydrogen,C₁-C₆-alkyl, or C₁-C₆-haloalkyl.

In certain embodiments, A₁ is unsubstituted. In certain embodiments, A₁is substituted with one or more R_(A). In certain embodiments, R_(A) ishalogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, or —O—R₉. In certain embodiments,R_(A) is —O—R₉ and R₉ is C₁-C₆-alkyl. In certain embodiments, R_(A) ishalogen, C₁-C₆-alkyl, or C₁-C₆-haloalkyl.

In certain embodiments, R₂ is —C(O)C(R₄)(R₅)(R₆) and each of R₄, R₅, andR₆ are C₁-C₆ alkyl. In certain embodiments, R₄ is methyl. In certainembodiments, R₅ is methyl. In certain embodiments, R₆ is methyl. Incertain embodiments, each of R₄, R₅, and R₆ are methyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and one or both of R₇ or R₈are C₁-C₆ alkyl. In certain embodiments, one or both of R₇ or R₈ aremethyl. In certain embodiments, one or both of R₇ or R₈ are ethyl. Incertain embodiments, one or both of R₇ or R₈ are propyl, such asn-propyl or isopropyl. In certain embodiments, one or both of R₇ or R₈are butyl, such as n-butyl, isobutyl, or sec-butyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and each of R₇ and R₈ areC₁-C₆ alkyl. In certain embodiments, both of R₇ and R₈ are methyl. Incertain embodiments, both of R₇ and R₈ are ethyl. In certainembodiments, both of R₇ and R₈ are propyl, such as n-propyl orisopropyl. In certain embodiments, both of R₇ and R₈ are butyl, such asn-butyl, isobutyl, or sec-butyl. In certain embodiments, one of R₇ or R₈is butyl and the other of R₇ or R₈ is ethyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and one or both of R₇ or R₈are C₃-C₈-cycloalkyl. In certain embodiments, both of R₇ and R₈ areC₃-C₈-cycloalkyl. In certain embodiments, both of R₇ and R₈ arecyclohexyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and one or both of R₇ or R₈are aryl. In certain embodiments, one or both of R₇ or R₈ are optionallysubstituted phenyl. In certain embodiments, one or both of R₇ or R₈ areunsubstituted phenyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and one of R₇ or R₈ isC₁-C₆ alkyl and the other of R₇ or R₈ is aryl. In certain embodiments,one of R₇ or R₈ is optionally substituted phenyl and the other of R₇ orR₈ is methyl or ethyl. In certain embodiments, one of R₇ or R₈ isunsubstituted phenyl and the other of R₇ or R₈ is methyl.

In certain embodiments, R₂ is dialkyl carbamoyl. In certain embodiments,R₂ is dimethyl carbamoyl. In certain embodiments, R₂ is diethylcarbamoyl. In certain embodiments, R₂ is dipropyl carbamoyl. In certainembodiments, R₂ is di(propan-2-yl)carbamoyl. In certain embodiments, R₂is dibutyl carbamoyl. In certain embodiments, R₂ isbis(2-methylpropyl)carbamoyl. In certain embodiments, R₂ isN-butyl-N-ethylcarbamoyl.

In certain embodiments, R₂ is N-methyl-N-phenylcarbamoyl.

In certain embodiments, R₂ is dicyclohexylcarbamoyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and R₇ and R₈ together withthe nitrogen atom to which they are attached form an optionallysubstituted saturated or partially saturated heterocyclic ring. Incertain embodiments, the heterocyclic ring is a non-aromatic ring. Incertain embodiments, the heterocyclic ring is a pyrrolidine. In certainembodiments, the heterocyclic ring is a piperidine. In certainembodiments, the heterocyclic ring is a morpholine. In certainembodiments, the heterocyclic ring is an azepane.

In certain embodiments, R₂ is —CH₂-A₁.

In certain embodiments, A₁ is an unsubstituted phenyl. In certainembodiments, R₂ is unsubstituted benzyl.

In certain embodiments, A₁ is a phenyl substituted with one or moreR_(A). In certain embodiments, R_(A) is haloalkyl. In certainembodiments, R_(A) is trifluoromethyl. In certain embodiments, R_(A) ishalogen. In certain embodiments, R_(A) is fluoro. In certainembodiments, R_(A) is chloro. In certain embodiments, R_(A) is analkoxy, such as methoxy. In certain embodiments, R₂ is substitutedbenzyl. In certain embodiments, R₂ is trifluoromethylbenzyl. In certainembodiments, R₂ is trifluorobenzyl. In certain embodiments, R₂ isfluorobenzyl. In certain embodiments, R₂ is difluorobenzyl. In certainembodiments, R₂ is chlorobenzyl. In certain embodiments, R₂ is4-methoxybenzyl.

In certain embodiments, A₁ is naphthalene. In certain embodiments, A₁ isbenzothiazole.

In certain embodiments, both a and b are a double bond. In certainembodiments, at least one of a and b are a single bond. In certainembodiments, both a and b are a single bond.

In one aspect, the present methods employ a compound of Formula (VII):

and salts thereof, wherein:

R₂ represents —C(O)C(R₄)(R₅)(R₆), wherein each of R₄, R₅, and R₆ areindependently selected from the group consisting of hydrogen,C₁-C₆-alkyl, C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl,heterocycloalkyl, arylalkyl, heteroarylalkyl, andC₃-C₈-cycloalkyl-C₁-C₄-alkyl; or

R₂ represents —C(O)N(R₇)(R₈), wherein each of R₇ and R₈ areindependently selected from the group consisting of C₁-C₆-alkyl,C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl, heterocycloalkyl,arylalkyl, heteroarylalkyl, and C₃-C₈-cycloalkyl-C₁-C₄-alkyl, or R₇ andR₈ together with the nitrogen atom to which they are attached form anoptionally substituted saturated or partially saturated heterocyclicring; or

R₂ represents —CH₂-A₁, wherein A₁ represents a 6- to 10-membered aryl ora 5- to 10-membered heteroaryl and A₁ is unsubstituted or substitutedwith one or more R_(A), wherein each R_(A) is independently selectedfrom the group consisting of halogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, and—O—R₉, where R₉ represents C₁-C₆-alkyl; and

each of a and b independently represents either a single bond or adouble bond.

In certain embodiments, R₂ is —C(O)C(R₄)(R₅)(R₆). Each of R₄, R₅, and R₆are independently selected from the group consisting of hydrogen,C₁-C₆-alkyl, C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl,heterocycloalkyl, arylalkyl, heteroarylalkyl, andC₃-C₈-cycloalkyl-C₁-C₄-alkyl. In certain embodiments, R₄ is C₁-C₆ alkyl.In certain embodiments, R₅ is C₁-C₆ alkyl. In certain embodiments, R₆ isC₁-C₆ alkyl. In certain embodiments, each of R₄, R₅, and R₆ are C₁-C₆alkyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈). In certain embodiments,each of R₇ and R₈ are independently selected from the group consistingof C₁-C₆-alkyl, C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl,heterocycloalkyl, arylalkyl, heteroarylalkyl, andC₃-C₈-cycloalkyl-C₁-C₄-alkyl. In certain embodiments, R₇ and R₈ togetherwith the nitrogen atom to which they are attached form an optionallysubstituted saturated or partially saturated heterocyclic ring. Forinstance R₇ and R₈, taken together with the atoms to which they areattached, can form, without limitation, an optionally substitutedsaturated heterocyclic ring such as

where X is O, S, or N(R_(B)). R_(B) is selected from hydrogen,C₁-C₆-alkyl, C₂-C₆-alkenyl, or C₂-C₆-alkynyl and n is 0, 1, 2, or 3.

In certain embodiments, R₂ is —CH₂-A₁ and A₁ is a 6- to 10-membered arylor a 5- to 10-membered heteroaryl. In certain embodiments, A₁ is phenyl,pyrazinyl, pyridinyl, pyrimidinyl, pyridazinyl, oxazolyl, thiazolyl,thienyl, furanyl, imidazolyl, pyrazolyl, triazolyl, benzoxazolyl,benzothienyl, benzimidazolyl, benzofuranyl, benzothiazolyl, indolyl,indenyl, naphthalenyl, quinolinyl, isoquinolinyl, quinoxalinyl,cinnolinyl, quinazolinyl, or phthalazinyl; each of which is optionallysubstituted. In certain embodiments, A₁ is

where Q is O, S, or N(R_(C)). R_(C) is selected from hydrogen,C₁-C₆-alkyl, or C₁-C₆-haloalkyl.

In certain embodiments, A₁ is unsubstituted.

In certain embodiments, A₁ is substituted with one or more R_(A). Incertain embodiments, R_(A) is halogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, or—O—R₉. In certain embodiments, R_(A) is —O—R₉ and R₉ is C₁-C₆-alkyl. Incertain embodiments, R_(A) is —O—R₉ and R₉ is methyl. In certainembodiments, R_(A) is halogen, C₁-C₆-alkyl, or C₁-C₆-haloalkyl.

In certain embodiments, A₁ is a phenyl substituted with one or moreR_(A). In certain embodiments, A₁ is a halophenyl or a dihalophenyl.

In certain embodiments, R₂ is —CH₂-A₁ and A₁ is a phenyl substitutedwith one or more R_(A). In certain embodiments, R_(A) is halogen. Incertain embodiments, R_(A) is fluoro. In certain embodiments, R₂ issubstituted benzyl. In certain embodiments, R₂ is fluorobenzyl. Incertain embodiments, R₂ is difluorobenzyl.

In certain embodiments, R₂ is —CH₂-A₁ and A₁ is a 7- to 10-membered aryloptionally substituted with one or more R_(A). Each R_(A) isindependently selected from the group consisting of halogen,C₁-C₆-alkyl, and C₁-C₆-haloalkyl.

In certain embodiments, R₂ is —CH₂-A₁ and A₁ is a 5- to 10-memberedheteroaryl optionally substituted with one or more R_(A). Each R_(A) isindependently selected from the group consisting of halogen,C₁-C₆-alkyl, and C₁-C₆-haloalkyl.

In certain embodiments, R₂ is —C(O)C(R₄)(R₅)(R₆) and each of R₄, R₅, andR₆ are C₁-C₆ alkyl. In certain embodiments, R₄ is methyl. In certainembodiments, R₅ is methyl. In certain embodiments, R₆ is methyl. Incertain embodiments, each of R₄, R₅, and R₆ are methyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and one or both of R₇ or R₈are C₁-C₆ alkyl. In certain embodiments, one or both of R₇ or R₈ aremethyl. In certain embodiments, one or both of R₇ or R₈ are ethyl. Incertain embodiments, one or both of R₇ or R₈ are propyl, such asn-propyl or isopropyl. In certain embodiments, one or both of R₇ or R₈are butyl, such as n-butyl, isobutyl, or sec-butyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and each of R₇ and R₈ areC₁-C₆ alkyl. In certain embodiments, both of R₇ and R₈ are ethyl. Incertain embodiments, both of R₇ and R₈ are propyl, such as n-propyl orisopropyl. In certain embodiments, both of R₇ and R₈ are butyl, such asn-butyl, isobutyl, or sec-butyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and one or both of R₇ or R₈are C₃-C₈-cycloalkyl. In certain embodiments, both of R₇ and R₈ areC₃-C₈-cycloalkyl. In certain embodiments, both of R₇ and R₈ arecyclohexyl.

In certain embodiments, R₂ is dialkyl carbamoyl. In certain embodiments,R₂ is diethyl carbamoyl. In certain embodiments, R₂ is dipropylcarbamoyl. In certain embodiments, R₂ is di(propan-2-yl)carbamoyl. Incertain embodiments, R₂ is dibutyl carbamoyl.

In certain embodiments, R₂ is dicycloalkyl carbamoyl. In certainembodiments, R₂ is dicyclohexylcarbamoyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and R₇ and R₈ together withthe nitrogen atom to which they are attached form an optionallysubstituted saturated or partially saturated heterocyclic ring. Incertain embodiments, the heterocyclic ring is a non-aromatic ring. Incertain embodiments, the heterocyclic ring is a morpholine.

In certain embodiments, both a and b are a double bond. In certainembodiments, at least one of a and b are a single bond. In certainembodiments, both a and b are a single bond.

In one aspect, the present methods employ a compound of Formula (VIII):

and salts thereof, wherein:

R₁ represents hydrogen or —C(O)R₃, wherein R₃ represents C₁-C₆-alkyl;and

R₂ represents —C(O)C(R₄)(R₅)(R₆), wherein each of R₄, R₅, and R₆ areindependently selected from the group consisting of hydrogen,C₁-C₆-alkyl, C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl,heterocycloalkyl, arylalkyl, heteroarylalkyl, andC₃-C₈-cycloalkyl-C₁-C₄-alkyl; or

R₂ represents —C(O)N(R₇)(R₈), wherein each of R₇ and R₈ areindependently selected from the group consisting of C₁-C₆-alkyl,C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl, heterocycloalkyl,arylalkyl, heteroarylalkyl, and C₃-C₈-cycloalkyl-C₁-C₄-alkyl, or R₇ andR₈ together with the nitrogen atom to which they are attached form anoptionally substituted saturated or partially saturated heterocyclicring; or

R₂ represents —CH₂-A₁, wherein A₁ represents a 6- to 10-membered aryl ora 5- to 10-membered heteroaryl and A₁ is unsubstituted or substitutedwith one or more R_(A), wherein each R_(A) is independently selectedfrom the group consisting of halogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, and—O—R₉, where R₉ represents C₁-C₆-alkyl.

In certain embodiments, R₁ is hydrogen.

In certain embodiments, R₁ is —C(O)R₃. In certain embodiments, R₃ isC₁-C₆-alkyl, such as methyl; ethyl; propyl, such as n-propyl orisopropyl; or butyl, such as n-butyl, isobutyl, or tert-butyl.

In certain embodiments, R₂ is —C(O)C(R₄)(R₅)(R₆). Each of R₄, R₅, and R₆are independently selected from the group consisting of hydrogen,C₁-C₆-alkyl, C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl,heterocycloalkyl, arylalkyl, heteroarylalkyl, andC₃-C₈-cycloalkyl-C₁-C₄-alkyl. In certain embodiments, R₄ is C₁-C₆ alkyl.In certain embodiments, R₅ is C₁-C₆ alkyl. In certain embodiments, R₆ isC₁-C₆ alkyl. In certain embodiments, each of R₄, R₅, and R₆ are C₁-C₆alkyl.

In certain embodiments, R₄, R₅, and R₆ are the same. For example, incertain embodiments, each of R₄, R₅, and R₆ are methyl. In certainembodiments, at least two of R₄, R₅, and R₆ are the same. In certainembodiments, R₄, R₅, and R₆ are different.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈). In certain embodiments,each of R₇ and R₈ are independently selected from the group consistingof C₁-C₆-alkyl, C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl,heterocycloalkyl, arylalkyl, heteroarylalkyl, andC₃-C₈-cycloalkyl-C₁-C₄-alkyl. In certain embodiments, R₇ and R₈ togetherwith the nitrogen atom to which they are attached form an optionallysubstituted saturated or partially saturated heterocyclic ring. Forinstance R₇ and R₈, taken together with the atoms to which they areattached, can form, without limitation, an optionally substitutedsaturated heterocyclic ring such as

where X is O, S, or N(R_(B)). R_(B) is selected from hydrogen,C₁-C₆-alkyl, C₂-C₆-alkenyl, or C₂-C₆-alkynyl and n is 0, 1, 2, or 3.

In certain embodiments, R₂ is —CH₂-A₁ and A₁ is a 6- to 10-membered arylor a 5- to 10-membered heteroaryl. In certain embodiments, A₁ is phenyl,pyrazinyl, pyridinyl, pyrimidinyl, pyridazinyl, oxazolyl, thiazolyl,thienyl, furanyl, imidazolyl, pyrazolyl, triazolyl, benzoxazolyl,benzothienyl, benzimidazolyl, benzofuranyl, benzothiazolyl, indolyl,indenyl, naphthalenyl, quinolinyl, isoquinolinyl, quinoxalinyl,cinnolinyl, quinazolinyl, or phthalazinyl; each of which is optionallysubstituted. In certain embodiments, A₁ is

where Q is O, S, or N(R_(C)). R_(C) is selected from hydrogen,C₁-C₆-alkyl, or C₁-C₆-haloalkyl.

In certain embodiments, A₁ is unsubstituted. In certain embodiments, A₁is substituted with one or more R_(A). In certain embodiments, R_(A) ishalogen, C₁-C₆-alkyl, or C₁-C₆-haloalkyl.

In certain embodiments, R₁ is —C(O)R₃ and R₃ is C₁-C₆-alkyl. In certainembodiments, R₃ is methyl. In certain embodiments, R₃ is propyl. Incertain embodiments, R₃ is n-propyl. In certain embodiments, R₃ isisopropyl. In certain embodiments, R₃ is butyl. In certain embodiments,R₃ is n-butyl. In certain embodiments, R₃ is isobutyl. In certainembodiments, R₃ is tert-butyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and one or both of R₇ or R₈are C₁-C₆ alkyl. In certain embodiments, one or both of R₇ or R₈ aremethyl. In certain embodiments, one or both of R₇ or R₈ are ethyl. Incertain embodiments, one or both of R₇ or R₈ are propyl, such asn-propyl or isopropyl. In certain embodiments, one or both of R₇ or R₈are butyl, such as n-butyl, isobutyl, or sec-butyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and each of R₇ and R₈ areC₁-C₆ alkyl. In certain embodiments, both of R₇ and R₈ are methyl. Incertain embodiments, both of R₇ and R₈ are ethyl. In certainembodiments, both of R₇ and R₈ are propyl, such as n-propyl orisopropyl. In certain embodiments, both of R₇ and R₈ are butyl, such asn-butyl, isobutyl, or sec-butyl. In certain embodiments, one of R₇ or R₈is butyl and the other of R₇ or R₈ is ethyl.

In certain embodiments, R₂ is dialkyl carbamoyl. In certain embodiments,R₂ is dimethyl carbamoyl. In certain embodiments, R₂ is diethylcarbamoyl. In certain embodiments, R₂ is dipropyl carbamoyl. In certainembodiments, R₂ is di(propan-2-yl)carbamoyl. In certain embodiments, R₂is dibutyl carbamoyl. In certain embodiments, R₂ isbis(2-methylpropyl)carbamoyl. In certain embodiments, R₂ isN-butyl-N-ethylcarbamoyl.

In certain embodiments, R₂ is —CH₂-A₁.

In certain embodiments, A₁ is a phenyl substituted with one or moreR_(A). In certain embodiments, R_(A) is haloalkyl. In certainembodiments, R_(A) is halogen. In certain embodiments, R_(A) is fluoro.

In certain embodiments, R₂ is substituted benzyl. In certainembodiments, R₂ is trifluoromethylbenzyl. In certain embodiments, R₂ isfluorobenzyl. In certain embodiments, R₂ is difluorobenzyl.

In certain embodiments, R₁ is hydrogen and R₂ is —C(O)N(CH₂CH₃)₂.

In certain embodiments, R₁ is —C(O)CH(CH₃)₂ and R₂ is —C(O)N(CH₂CH₃)₂.

In certain embodiments, R₁ is hydrogen and R₂ is fluorobenzyl.

In certain embodiments, R₁ is hydrogen and R₂ is

In certain embodiments, R₁ is hydrogen and R₂ is difluorobenzyl.

In certain embodiments, R₁ is hydrogen and R₂ is

In one aspect, the present invention includes compounds of Formula (IX):

and salts thereof, wherein:

R₁ represents hydrogen or —C(O)R₃, wherein R₃ represents an optionallysubstituted C₁-C₆-alkyl or C₁-C₆-haloalkyl;

R₂ represents —C(O)C(R₄)(R₅)(R₆), wherein each of R₄, R₅, and R₆ areindependently selected from the group consisting of C₁-C₆-alkyl,C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl, heterocycloalkyl,arylalkyl, heteroarylalkyl, and C₃-C₈-cycloalkyl-C₁-C₄-alkyl; or

R₂ represents —C(O)N(R₇)(R₈), wherein each of R₇ and R₈ areindependently selected from the group consisting of hydrogen,C₁-C₆-alkyl, C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl,heterocycloalkyl, arylalkyl, heteroarylalkyl, andC₃-C₈-cycloalkyl-C₁-C₄-alkyl, or R₇ and R₈ together with the nitrogenatom to which they are attached form an optionally substituted saturatedor partially saturated heterocyclic ring; or

R₂ represents —CH₂-A₁, wherein A₁ represents a 6- to 10-membered aryl ora 5- to 10-membered heteroaryl and A₁ is unsubstituted or substitutedwith one or more R_(A), wherein each R_(A) is independently selectedfrom the group consisting of halogen, C₁-C₆-alkyl, C₁-C₆-alkoxy, andC₁-C₆-haloalkyl;

R₁₁ represents an optionally substituted C₁-C₆-alkyl, C₁-C₆-haloalkyl,aryl, heteroaryl, C₃-C₈-cycloalkyl, heterocycloalkyl, arylalkyl,heteroarylalkyl, or C₃-C₈-cycloalkyl-C₁-C₄-alkyl; and

each of a and b independently represents either a single bond or adouble bond.

In certain embodiments, R₁ is hydrogen.

In certain embodiments, R₁ is —C(O)R₃. In certain embodiments, R₃ isC₁-C₆-alkyl, such as methyl; ethyl; propyl, such as n-propyl orisopropyl; or butyl, such as n-butyl, isobutyl, or tert-butyl. Incertain embodiments, R₃ is methyl. In certain embodiments, R₃ is ethyl.In certain embodiments, R₃ is propyl. In certain embodiments, R₃ isn-propyl. In certain embodiments, R₃ is isopropyl. In certainembodiments, R₃ is butyl. In certain embodiments, R₃ is n-butyl. Incertain embodiments, R₃ is isobutyl. In certain embodiments, R₃ istert-butyl. In certain embodiments, R₃ is C₁-C₆-haloalkyl.

In certain embodiments, R₂ is —C(O)C(R₄)(R₅)(R₆). Each of R₄, R₅, and R₆are independently selected from the group consisting of C₁-C₆-alkyl,C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl, heterocycloalkyl,arylalkyl, heteroarylalkyl, and C₃-C₈-cycloalkyl-C₁-C₄-alkyl. In certainembodiments, R₄ is C₁-C₆ alkyl. In certain embodiments, R₅ is C₁-C₆alkyl. In certain embodiments, R₆ is C₁-C₆ alkyl. In certainembodiments, each of R₄, R₅, and R₆ are C₁-C₆ alkyl.

In certain embodiments, R₄, R₅, and R₆ are the same. For example, incertain embodiments, each of R₄, R₅, and R₆ are methyl. In certainembodiments, at least two of R₄, R₅, and R₆ are the same. In certainembodiments, R₄, R₅, and R₆ are different.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈). In certain embodiments,each of R₇ and R₈ are independently selected from the group consistingof hydrogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, aryl, heteroaryl,C₃-C₈-cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, andC₃-C₈-cycloalkyl-C₁-C₄-alkyl. In certain embodiments, R₇ and R₈ togetherwith the nitrogen atom to which they are attached form an optionallysubstituted saturated or partially saturated heterocyclic ring. Forinstance R₇ and R₈, taken together with the atoms to which they areattached, can form, without limitation, an optionally substitutedsaturated heterocyclic ring such as

where X is O, S, or N(R_(B)). R_(B) is selected from hydrogen,C₁-C₆-alkyl, C₂-C₆-alkenyl, or C₂-C₆-alkynyl and n is 0, 1, 2, or 3.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and one or both of R₇ or R₈are C₁-C₆ alkyl. In certain embodiments, one or both of R₇ or R₈ aremethyl. In certain embodiments, one or both of R₇ or R₈ are ethyl. Incertain embodiments, one or both of R₇ or R₈ are propyl, such asn-propyl or isopropyl. In certain embodiments, one or both of R₇ or R₈are butyl, such as n-butyl, isobutyl, or sec-butyl.

In certain embodiments, R₂ is —C(O)N(R₇)(R₈) and each of R₇ and R₈ areC₁-C₆ alkyl. In certain embodiments, both of R₇ and R₈ are methyl. Incertain embodiments, both of R₇ and R₈ are ethyl. In certainembodiments, both of R₇ and R₈ are propyl, such as n-propyl orisopropyl. In certain embodiments, both of R₇ and R₈ are butyl, such asn-butyl, isobutyl, or sec-butyl. In certain embodiments, one of R₇ or R₈is butyl and the other of R₇ or R₈ is ethyl.

In certain embodiments, R₂ is dialkyl carbamoyl. In certain embodiments,R₂ is dimethyl carbamoyl. In certain embodiments, R₂ is diethylcarbamoyl. In certain embodiments, R₂ is dipropyl carbamoyl. In certainembodiments, R₂ is di(propan-2-yl)carbamoyl. In certain embodiments, R₂is dibutyl carbamoyl. In certain embodiments, R₂ isbis(2-methylpropyl)carbamoyl. In certain embodiments, R₂ isN-butyl-N-ethylcarbamoyl.

In certain embodiments, when both a and b are a double bond, R₁ isC(O)CH₃, R₁₁ is CH₃, and neither R₇ nor R₈ are hydrogen.

In certain embodiments, R₂ is —CH₂-A₁ and A₁ is a 6- to 10-membered arylor a 5- to 10-membered heteroaryl. In certain embodiments, A₁ is phenyl,pyrazinyl, pyridinyl, pyrimidinyl, pyridazinyl, oxazolyl, thiazolyl,thienyl, furanyl, imidazolyl, pyrazolyl, triazolyl, benzoxazolyl,benzothienyl, benzimidazolyl, benzofuranyl, benzothiazolyl, indolyl,indenyl, naphthalenyl, quinolinyl, isoquinolinyl, quinoxalinyl,cinnolinyl, quinazolinyl, or phthalazinyl; each of which is optionallysubstituted. In certain embodiments, A₁ is

where Q is O, S, or N(R_(C)). R_(C) is selected from hydrogen;C₁-C₆-alkyl, or C₁-C₆-haloalkyl.

In certain embodiments, A₁ is unsubstituted. In certain embodiments, A₁is substituted with one or more R_(A). In certain embodiments, R_(A) ishalogen, C₁-C₆-alkyl, C₁-C₆-alkoxy, or C₁-C₆-haloalkyl.

In certain embodiments, A₁ is a phenyl substituted with one or moreR_(A). In certain embodiments, R_(A) is haloalkyl. In certainembodiments, R_(A) is halogen. In certain embodiments, R_(A) is fluoro.

In certain embodiments, R₂ is substituted benzyl. In certainembodiments, R₂ is trifluoromethylbenzyl. In certain embodiments, R₂ isfluorobenzyl. In certain embodiments, R₂ is difluorobenzyl.

In certain embodiments, R₁₁ is C₁-C₆-alkyl, such as methyl; ethyl;propyl, such as n-propyl or isopropyl; or butyl, such as n-butyl,isobutyl, or tert-butyl. In certain embodiments, R₁₁ is methyl. Incertain embodiments, R₁₁ is ethyl. In certain embodiments, R₁₁ ispropyl. In certain embodiments, R₁₁ is n-propyl. In certain embodiments,R₁₁ is isopropyl. In certain embodiments, R₁₁ is butyl. In certainembodiments, R₁₁ is n-butyl. In certain embodiments, R₁₁ is tert-butyl.In certain embodiments, R₁₁ is C₁-C₆-haloalkyl.

In certain embodiments, R₁ is —C(O)CH₃; R₂ is —C(O)N(CH₂CH₃)₂; and R₁₁is —CH₂CH₃.

In certain embodiments, R₁ is hydrogen; R₂ is —C(O)N(CH₂CH₃)₂; and R₁₁is —CH₂CH₃.

In certain embodiments, R₁ is —C(O)CH₂CH₃; R₂ is —C(O)N(CH₂CH₃)₂; andR₁₁ is —CH₂CH₃.

In certain embodiments, R₁ is —C(O)CH₃; R₂ is

and R₁₁ is —CH₂CH₃.

In certain embodiments, R₁ is hydrogen; R₂ is

and R₁₁ is —CH₂CH₃.

In certain embodiments, R₁ is —C(O)CH₃; R₂ is —C(O)N(CH₂CH₃)₂; and R₁₁is —CH₃.

In certain embodiments, R₁ is hydrogen; R₂ is —C(O)N(CH₂CH₃)₂; and R₁₁is —CH₃.

In certain embodiments, R₁ is hydrogen; R₂ is —C(O)N(CH₂CH₃)₂; and R₁₁is —CH(CH₃)₂.

In certain embodiments, R₁ is —C(O)CH₃; R₂ is

and R₁₁ is —CH₃.

In certain embodiments, R₁ is hydrogen; R₂ is

and R₁₁ is —CH₃.

In certain embodiments, R₁—C(O)CH₃; R₂ is

and R₁₁ is —CH(CH₃)₂.

In certain embodiments, R₁ is hydrogen; R₂ is

and R₁₁ is —CH(CH₃)₂. Anti-Wolbachia activity of a compound can bedetermined using various methods known to those of skill in the art,including in vitro and in vivo assays. For example, in certainembodiments, a whole organism Wolbachia cell-based assay is used toscreen compounds. Such an assay is described in Turner et al., (2006) J.Immunol. 7:1240-1249 and Johnston et al., (2010) Parasit Vectors. 3:99.In certain embodiments, in vitro nematode screening is employed, using,for example, adult male Onchocerca gutturosa or B. malayi. Townson S, etal., (2006) Filaria J. 5:4. For in vivo nematode screening, establishedanimal models of filarial infection may be utilized and includeLitomosoides sigmodontis in mice (Hoerauf A, et al. (1999) Journal ofClinical Investigation 103(1):11-18) and B. malayi in gerbils (Ash andRiley, (1970) J Parasitol. 56(5):969-73). For in vivo models, thereduction of Wolbachia load following treatment can be measured by qPCR.(McGarry H, et al Mol Biochem Parasitol. (2004) 135(1):57-67, Halliday,A et al. (2014) Parasit Vectors 7, 472).

It is to be understood that compounds disclosed herein may exhibit thestereoisomerism, including geometric isomerism, and/or tautomerism.

For example, the present compounds may exist as stereoisomers whereasymmetric or chiral centers are present. These stereoisomers are “R” or“S” depending on the configuration of substituents around the chiralcarbon atom. The terms “R” and “S” used herein are configurations asdefined in IUPAC 1974 Recommendations for Section E, FundamentalStereochemistry, Pure Appl. Chem., 1976, 45: 13-30.

The present disclosure contemplates various stereoisomers and mixturesthereof and these are specifically included within the scope of theinvention. Stereoisomers include enantiomers and diastereomers, andmixtures of enantiomers or diastereomers. Individual stereoisomers ofthe present compounds may be prepared synthetically from commerciallyavailable starting materials which contain asymmetric or chiral centersor by preparation of racemic mixtures followed by resolution.

The present disclosure also contemplates various geometric isomers andmixtures thereof resulting from the disposition of substituents around acarbon-carbon double bond, a carbon-nitrogen double bond, a cycloalkylgroup, or a heterocycle group.

The present disclosure also contemplates various tautomers and mixturesthereof resulting from, for example, interconversion between keto andenol forms.

Thus, the formulae drawings within this specification can represent onlyone of the possible tautomeric or stereoisomeric forms. It is to beunderstood that the invention encompasses any tautomeric orstereoisomeric form, and mixtures thereof, and is not to be limitedmerely to any one tautomeric or stereoisomeric form utilized within thenaming of the compounds or formulae drawings.

The present disclosure also contemplates isotopically-labeled compounds,which are identical to those recited in Formula (I), Formula (I-1),Formula (II), Formula (III), Formula (IV), Formula (V), Formula (VI),Formula (VII), Formula (VIII), or Formula (IX) but for the fact that oneor more atoms are replaced by an atom having an atomic mass or massnumber different from the atomic mass or mass number usually found innature. Examples of isotopes suitable for inclusion in suchisotopically-labeled compounds are hydrogen, carbon, nitrogen, oxygen,phosphorus, fluorine, and chlorine, such as, but not limited to ²H, ³H,¹³C, ¹⁴C, ¹⁵N, ¹⁸O, ¹⁷O, ³¹P, ³²P, ³⁵S, ¹⁸F, and ³⁶Cl, respectively.Substitution with heavier isotopes such as deuterium, i.e., ²H, canafford certain therapeutic advantages resulting from greater metabolicstability, for example increased in vivo half-life or reduced dosagerequirements and, hence, may be preferred in some circumstances.Compounds incorporating positron-emitting isotopes are useful in medicalimaging and positron-emitting tomography (PET) studies for determiningthe distribution of receptors. Suitable positron-emitting isotopes thatcan be incorporated in compounds of Formula (I), Formula (I-1), Formula(II), Formula (III), Formula (IV), Formula (V), Formula (VI), Formula(VII), Formula (VIII), or Formula (IX) are ¹¹C, ¹³N, ¹⁵O, and ¹⁸F.Isotopically-labeled compounds of Formula (I), Formula (I-1), Formula(II), Formula (III), Formula (IV), Formula (V), Formula (VI), Formula(VII), Formula (VIII), or Formula (IX) can generally be prepared byconventional techniques known to those skilled in the art or byprocesses analogous to those described in the accompanying Schemes andExamples using appropriate isotopically-labeled reagent in place ofnon-isotopically-labeled reagent.

D. METHODS FOR PREPARING COMPOUNDS

The compounds described herein can be better understood in connectionwith the following synthetic schemes and methods which illustrate ameans by which the compounds can be prepared.

Certain compounds that may be used in carrying out the present methodsmay be prepared from Tylosin A as described below.

As indicated in Scheme 1, Tylosin A (or a salt thereof) is selectivelyacylated at the 2′-hydroxyl using an acylating agent such as an acidanhydride or the like, in a solvent such as acetone or chloroform orethanol or the like. Alternatively, the acylating agent may be generatedin situ, using a carboxylic acid and an activating agent such asisobutyl chloformate or the like, optionally in the presence of a basesuch as N-methylmorpholine or the like.

The resultant 2′-ester may be converted to the corresponding3″/4″-cyclic tin reagent through reaction with dibutyltin oxide, ordibutyltin dichloride, or the like, optionally in the presence of a basesuch as 1,2,2,6,6,-pentamethylpiperidine or the like, in a solvent suchas toluene or THF or the like. As indicated in Scheme 2, the resultanttin reagent is not generally isolated, but is reacted directly

a) with an acylating agent, such as an acid chloride or the like, togive the corresponding 4″-acylated analog;

b) with a carbamylating agent, such diethylcarbamyl chloride or thelike, to give the corresponding 4″-carbamate analog; or

c) with a benzylating agent, for example 4-fluorobenzyl brominde or thelike, optionally in the presence of an iodide source such astetra-n-butylammonium iodide or the like, to give the corresponding4″-benzylated analog.

In the specific case where the 2′-substituent is acetyl, the resultant2′-OAc/4″-substituted analog may (as in Scheme 3) be warmed in analcohol like methanol or the like, optionally in the presence of acatalyst like solid sodium bicarbonate or the like, to hydrolyze the2′-ester, resulting in the production of a 2′-unsubstituted,4″-substituted analog.

To prepare compounds that are simultaneously modified at the 2′, 4″, and4′″ positions, a 2′/4″-derivatized intermediate (prepared as describedin Scheme 2) is treated with an acylating agent like acetic anhydride,or propionic anhydride, or the like, in a basic solvent like pyridine orlutidine or the like, as shown in Scheme 4. In the specific case wherethe 2′-substituent is acetyl, the resultant 2′-OAc/4″/4′″-substitutedanalog may be warmed in an alcohol like methanol or the like, optionallyin the presence of a catalyst like solid sodium bicarbonate or the like,to hydrolyze the 2′-ester, resulting in the production of a2′-unsubstituted, 4″/4′″-disubstituted analog.

To prepare compounds that are reduced at the 10/11 and/or 12/13positions, the corresponding unsaturated compound may be treated withhydrogen gas, or a hydrogen source like ammonium formate or the like, inthe presence of a hydrogenation catalyst like palladium-on-carbon orplatinum-on-carbon or Raney nickel or the like, in a solvent likeethanol or ethyl acetate or the like. By controlling the time,temperature, solvent and concentration of the reaction, one or both ofthe 10/11 and 12/13 double bonds may be reduced to single bonds.

The compounds and intermediates that can be used in the methodsdescribed herein may be isolated and purified by conventional methods inthe field of organic synthesis. Examples of conventional methods forisolating and purifying compounds can include, but are not limited to,chromatography on solid supports such as silica gel, alumina, or silicaderivatized with alkylsilane groups, by recrystallization at high or lowtemperature with an optional pretreatment with activated carbon,thin-layer chromatography, distillation at various pressures,sublimation under vacuum, and trituration, as described for instance in“Vogel's Textbook of Practical Organic Chemistry”, 5th edition (1989),by Furniss, Hannaford, Smith, and Tatchell, pub. Longman Scientific &Technical, Essex CM20 2JE, England.

Certain compounds that can be used in the methods described herein haveat least one basic nitrogen whereby the compound can be treated with anacid to form a desired salt. For example, a compound may be reacted withan acid at or above room temperature to provide the desired salt, whichis deposited, and collected by filtration after cooling. Examples ofacids suitable for the reaction include, but are not limited to tartaricacid, lactic acid, succinic acid, as well as mandelic, atrolactic,methanesulfonic, ethanesulfonic, toluenesulfonic, naphthalenesulfonic,benzenesulfonic, carbonic, fumaric, maleic, gluconic, acetic, propionic,salicylic, hydrochloric, hydrobromic, phosphoric, sulfuric, citric,hydroxybutyric, camphorsulfonic, malic, phenylacetic, aspartic, orglutamic acid, and the like. In certain embodiments, a compound may bereacted with a weak acid to provide the desired salt. Examples ofsuitable weak acids, but are not limited to, tartaric acid, lactic acid,acetic acid, propionic acid, citric acid, malic acid, and the like. Incertain embodiments, the acid is tartaric acid.

Optimum reaction conditions and reaction times for each individual stepcan vary depending on the particular reactants employed and substituentspresent in the reactants used. Unless otherwise specified, solvents,temperatures and other reaction conditions can be readily selected.Specific procedures are provided in the Examples section. Reactions canbe worked up in the conventional manner, e.g. by eliminating the solventfrom the residue and further purified according to methodologiesgenerally known in the art such as, but not limited to, crystallization,distillation, extraction, trituration and chromatography. Unlessotherwise described, the starting materials and reagents are eithercommercially available or can be prepared by one skilled in the art fromcommercially available materials using methods described in the chemicalliterature.

Routine experimentations, including appropriate manipulation of thereaction conditions, reagents and sequence of the synthetic route,protection of any chemical functionality that is not compatible with thereaction conditions, and deprotection at a suitable point in thereaction sequence of the method are included in the scope of theinvention. Suitable protecting groups and the methods for protecting anddeprotecting different substituents using such suitable protectinggroups are well known; examples of which can be found in P G M Wuts andT W Greene, Greene's Protective Groups in Organic Synthesis (4th ed.),John Wiley & Sons, NY (2006), which is incorporated herein by referencein its entirety. Synthesis of the compounds mentioned herein can beaccomplished by methods analogous to those described in the syntheticschemes described hereinabove.

Starting materials, if not commercially available, can be prepared byprocedures selected from standard organic chemical techniques,techniques that are analogous to the synthesis of known, structurallysimilar compounds, or techniques that are analogous to the abovedescribed schemes or the procedures described in the synthetic examplessection.

When an optically active form of a compound is required, it can beobtained by carrying out one of the procedures described herein using anoptically active starting material (prepared, for example, by asymmetricinduction of a suitable reaction step), or by resolution of a mixture ofthe stereoisomers of the compound or intermediates using a standardprocedure (such as chromatographic separation, recrystallization orenzymatic resolution).

Similarly, when a pure geometric isomer of a compound is required, itcan be obtained by carrying out one of the above procedures using a puregeometric isomer as a starting material, or by resolution of a mixtureof the geometric isomers of the compound or intermediates using astandard procedure such as chromatographic separation.

It can be appreciated that the synthetic schemes and specific examplesas illustrated in the Examples section are illustrative and are not tobe read as limiting the scope of the invention as it is defined in theappended claims. All alternatives, modifications, and equivalents of thesynthetic methods and specific examples are included within the scope ofthe claims.

E. COMPOSITIONS FOR PREVENTION OR TREATMENT OF FILARIASIS

In at least one aspect, the present invention includes a composition forpreventing or treating filariasis. The composition for preventing ortreating filariasis includes a compound described herein or a saltthereof. In certain embodiments, the composition for preventing ortreating filariasis comprises a compound of Formula (I) or a saltthereof. In certain embodiments, the composition for preventing ortreating filariasis comprises a compound of Formula (I-1) or a saltthereof. In certain embodiments, the composition for preventing ortreating filariasis comprises a compound of Formula (II) or a saltthereof. In certain embodiments, the composition for preventing ortreating filariasis comprises a compound of Formula (III) or a saltthereof. In certain embodiments, the composition for preventing ortreating filariasis comprises a compound of Formula (IV) or a saltthereof. In certain embodiments, the composition for preventing ortreating filariasis comprises a compound of Formula (V) or a saltthereof. In certain embodiments, the composition for preventing ortreating filariasis comprises a compound of Formula (VI) or a saltthereof. In certain embodiments, the composition for preventing ortreating filariasis comprises a compound of Formula (VII) or a saltthereof. In certain embodiments, the composition for preventing ortreating filariasis comprises a compound of Formula (VIII) or a saltthereof. In certain embodiments, the composition for preventing ortreating filariasis comprises a compound of Formula (IX) or a saltthereof.

In certain embodiments, the composition for preventing or treatingfilariasis comprises one or more conventional pharmaceuticallyacceptable carriers. Pharmaceutically acceptable carriers include,without limitation, a non-toxic, inert solid, semi-solid or liquidfiller, diluent, encapsulating material or formulation auxiliary of anytype. Some examples of materials which can serve as pharmaceuticallyacceptable carriers are sugars such as lactose, glucose and sucrose;starches such as corn starch and potato starch; cellulose and itsderivatives such as sodium carboxymethyl cellulose, ethyl cellulose andcellulose acetate; powdered tragacanth; malt; gelatin; talc; excipientssuch as cocoa butter and suppository waxes; oils such as peanut oil,cottonseed oil, safflower oil, sesame oil, olive oil, corn oil andsoybean oil; glycols such as propylene glycol; esters such as ethyloleate and ethyl laurate; agar; buffering agents such as magnesiumhydroxide and aluminun hydroxide; alginic acid; pyrogen-free water;isotonic saline; Ringer's solution; ethyl alcohol, and phosphate buffersolutions, as well as other non-toxic compatible lubricants such assodium lauryl sulfate and magnesium stearate, as well as coloringagents, releasing agents, coating agents, sweetening, flavoring andperfuming agents, preservatives and antioxidants can also be present inthe composition for preventing or treating filariasis, according to thejudgment of one skilled in the art of formulations. Formulation of drugsis generally discussed in, for example, Hoover, J., Remington'sPharmaceutical Sciences (Mack Publishing Co., 1975) and Ansel'sPharmaceutical Dosage Forms and Drug Delivery Systems (LippincottWilliams & Wilkins, 2005).

In at least one aspect, the present invention includes pharmaceuticalcompositions for preventing or treating filariasis comprising atherapeutically effective amount of a compound described herein incombination with one or more pharmaceutically acceptable carriers. Incertain embodiments, the pharmaceutical compositions for preventing ortreating filariasis comprise a compound of formula (I) or a salt thereofformulated together with one or more pharmaceutically acceptablecarriers. In certain embodiments, the pharmaceutical compositions forpreventing or treating filariasis comprise a compound of formula (I-1)or a salt thereof formulated together with one or more pharmaceuticallyacceptable carriers. In certain embodiments, the pharmaceuticalcompositions for preventing or treating filariasis comprise a compoundof formula (II) or a salt thereof formulated together with one or morepharmaceutically acceptable carriers. In certain embodiments, thepharmaceutical compositions for preventing or treating filariasiscomprise a compound of formula (III) or a salt thereof formulatedtogether with one or more pharmaceutically acceptable carriers. Incertain embodiments, the pharmaceutical compositions for preventing ortreating filariasis comprise a compound of formula (IV) or a saltthereof formulated together with one or more pharmaceutically acceptablecarriers. In certain embodiments, the pharmaceutical compositions forpreventing or treating filariasis comprise a compound of formula (V) ora salt thereof formulated together with one or more pharmaceuticallyacceptable carriers. In certain embodiments, the pharmaceuticalcompositions for preventing or treating filariasis comprise a compoundof formula (VI) or a salt thereof formulated together with one or morepharmaceutically acceptable carriers. In certain embodiments, thepharmaceutical compositions for preventing or treating filariasiscomprise a compound of formula (VII) or a salt thereof formulatedtogether with one or more pharmaceutically acceptable carriers. Incertain embodiments, the pharmaceutical compositions for preventing ortreating filariasis comprise a compound of formula (VIII) or a saltthereof formulated together with one or more pharmaceutically acceptablecarriers. In certain embodiments, the pharmaceutical compositions forpreventing or treating filariasis comprise a compound of formula (IX) ora salt thereof formulated together with one or more pharmaceuticallyacceptable carriers.

Pharmaceutical compositions may be formulated for any route ofadministration. The pharmaceutical compositions can be administered tohumans and other animals orally, nasally, rectally, parenterally,intracisternally, intravaginally, intraperitoneally, topically (as bypowders, ointments or drops), or bucally. The term “parenterally”, asused herein, refers to modes of administration which includeintravenous, intramuscular, intraperitoneal, intrasternal, subcutaneous,intraarticular injection and infusion.

In certain embodiments, the pharmaceutical compositions are formulatedfor oral administration in solid or liquid form.

In certain embodiments, the pharmaceutical composition is a solid dosageform for oral administration. Solid dosage forms for oral administrationinclude capsules, tablets, pills, powders, and granules. In certainembodiments, the pharmaceutical composition includes, for example,lactose, sucrose, starch powder, cellulose esters of alkanoic acids,cellulose alkyl esters, talc, stearic acid, magnesium stearate,magnesium oxide, sodium and calcium salts of phosphoric and sulfuricacids, gelatin, acacia gum, sodium alginate, polyvinylpyrrolidone,and/or polyvinyl alcohol. In certain embodiments, the pharmaceuticalcomposition is tableted or encapsulated for convenient administration.In certain embodiments, such capsules or tablets contain acontrolled-release formulation, as can be provided in, for example, adispersion of the compound or salt in hydroxypropylmethyl cellulose. Inthe case of capsules, tablets, and pills, the dosage forms also cancomprise buffering agents, such as sodium citrate, or magnesium orcalcium carbonate or bicarbonate. Tablets and pills additionally can beprepared with enteric coatings.

In certain embodiments, the pharmaceutical composition is a liquiddosage form for oral administration. Liquid dosage forms for oraladministration include, for example, pharmaceutically acceptableemulsions (including both oil-in-water and water-in-oil emulsions),solutions (including both aqueous and non-aqueous solutions),suspensions (including both aqueous and non-aqueous suspensions),syrups, and elixirs. In certain embodiments, the liquid dosage formscontain inert diluents commonly used in the art such as, for example,water or other solvents, solubilizing agents and emulsifiers such asethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzylalcohol, benzyl benzoate, propylene glycol, 1,3-butylene glycol,dimethyl formamide, oils (in particular, cottonseed, groundnut, corn,germ, olive, castor and sesame oils), glycerol, tetrahydrofurfurylalcohol, polyethylene glycols and fatty acid esters of sorbitan andmixtures thereof. In addition, in certain embodiments, oralcompositions, also include wetting, emulsifying, suspending, flavoring(e.g., sweetening), and/or perfuming agents.

Parenteral administration includes subcutaneous injections, intravenousinjections, intramuscular injections, intrasternal injections, andinfusion. Injectable preparations (e.g., sterile injectable aqueous oroleaginous suspensions) can be formulated according to the known artusing suitable dispersing, wetting agents, and/or suspending agents.Acceptable vehicles and solvents include, for example, water,1,3-butanediol, Ringer's solution, isotonic sodium chloride solution,bland fixed oils (e.g., synthetic mono- or diglycerides), fatty acids(e.g., oleic acid), dimethyl acetamide, surfactants (e.g., ionic andnon-ionic detergents), and/or polyethylene glycols.

In certain embodiments, the pharmaceutical composition is for parenteraladministration. In certain embodiments, formulations for parenteraladministration are prepared from sterile powders or granules having oneor more of the carriers or excipients mentioned for use in theformulations for oral administration. In certain embodiments, a compoundor salt thereof is dissolved in water, polyethylene glycol, propyleneglycol, ethanol, corn oil, cottonseed oil, peanut oil, sesame oil,benzyl alcohol, sodium chloride, and/or various buffers. In certainembodiments, the pH is adjusted, if necessary, with a suitable acid,base, or buffer.

In certain embodiments, the pharmaceutical composition is for rectal orvaginal administration. Compositions for rectal or vaginaladministration are preferably suppositories that can be prepared by, forexample, mixing a compound or salt thereof with a suitable nonirritatingcarrier or excipient that is solid at ordinary room temperatures, butliquid at body temperature. Suitable carriers or excipients include, forexample, cocoa butter; synthetic mono-, di-, or triglycerides, fattyacids, and/or polyethylene glycols.

Topical administration includes the use of transdermal administration,such as transdermal patches or iontophoresis devices.

Other carriers and modes of administration known in the pharmaceuticalart also may be used.

In at least one aspect, compounds described herein are used in the formof pharmaceutically acceptable salts or esters, or amides derived frominorganic or organic acids. In certain embodiments, pharmaceuticallyacceptable salts are those salts that are, within the scope of soundmedical judgment, suitable for use in contact with the tissues of humansand lower animals without undue toxicity, irritation, allergic response,and the like, and are commensurate with a reasonable benefit/risk ratio.Pharmaceutically acceptable salts are well-known in the art. The saltscan be prepared in situ during the final isolation and purification ofthe compounds or separately by, for example, reacting a free basefunction with a suitable organic acid.

Representative pharmaceutically acceptable salts include, but are notlimited to, acetate, adipate, alginate, citrate, aspartate, benzoate,benzenesulfonate, bisulfate, butyrate, camphorate, camphorsulfonate,digluconate, glycerophosphate, hemisulfate, heptanoate, hexanoate,fumarate, hydrochloride, hydrobromide, hydroiodide,2-hydroxyethansulfonate (isethionate), lactate, maleate,methanesulfonate, nicotinate, 2-naphthalenesulfonate, oxalate, pamoate,pectinate, persulfate, 3-phenylpropionate, picrate, pivalate,propionate, succinate, tartrate, thiocyanate, phosphate, glutamate,bicarbonate, p-toluenesulfonate and undecanoate.

Also, the basic nitrogen-containing groups can be quaternized with suchagents as lower alkyl halides such as methyl, ethyl, propyl, and butylchlorides, bromides and iodides; dialkyl sulfates such as dimethyl,diethyl, dibutyl and diamyl sulfates; long chain halides such as decyl,lauryl, myristyl and stearyl chlorides, bromides and iodides; arylalkylhalides such as benzyl and phenethyl bromides and others. Water oroil-soluble or dispersible products are thereby obtained.

In certain embodiments, pharmaceutically acceptable acid addition saltsof the compounds of Formula (I), (I-1), (II), (III), (IV), (V), (VI),(VII), (VIII), or (IX) are prepared from an inorganic or organic acid.Examples of acids which can be employed to form pharmaceuticallyacceptable acid addition salts include inorganic acids such ashydrochloric acid, hydrobromic acid, sulphuric acid and phosphoric acidand organic acids such as acetic acid, oxalic acid, maleic acid,succinic acid, tartaric acid, and citric acid. In certain embodiments, aweak acid, including, but not limited to, tartaric acid, lactic acid,acetic acid, propionic acid, citric acid, malic acid, and the like, canbe employed to form pharmaceutically acceptable acid addition salt.

In certain embodiments, pharmaceutically acceptable base addition saltsof the compounds of Formula (I), (I-1), (II), (III), (IV), (V), (VI),(VII), (VIII), or (IX) include, for example, metallic salts and organicsalts. In certain embodiments, pharmaceutically acceptable saltsinclude, but are not limited to, cations based on alkali metals oralkaline earth metals such as lithium, sodium, potassium, calcium,magnesium, and aluminum salts, and the like, and nontoxic quaternaryammonia and amine cations including ammonium, tetramethylammonium,tetraethylammonium, methylammonium, dimethylammonium, trimethylammonium,triethylammonium, diethylammonium, ethylammonium and the like. Otherrepresentative organic amines useful for the formation of base additionsalts include ethylenediamine, ethanolamine, diethanolamine, piperidine,and piperazine.

In at least one aspect, the present invention includes a compositioncomprising one or more macrolide compounds or a salt thereof. In certainembodiments, at least 50% of the macrolide compounds in the compositionare a compound of Formula (I), (I-1), (II), (III), (IV), (V), (VI),(VII), (VIII), (IX), or a salt thereof. In certain embodiments, at least60% of the macrolide compounds in the composition are a compound ofFormula (I), (I-1), (II), (III), (IV), (V), (VI), (VII), (VIII), (IX),or a salt thereof. In certain embodiments, at least 80% of the macrolidecompounds in the composition are a compound of Formula (I), (I-1), (II),(III), (IV), (V), (VI), (VII), (VIII), (IX), or a salt thereof. Incertain embodiments, at least 80% of the macrolide compounds in thecomposition are a compound of Formula (I), (I-1), (II), (III), (IV),(V), (VI), (VII), (VIII), (IX), or a salt thereof. In certainembodiments, at least 90% of the macrolide compounds in the compositionare a compound of Formula (I), (I-1), (II), (III), (IV), (V), (VI),(VII), (VIII), (IX), or a salt thereof. In certain embodiments, at least95% of the macrolide compounds in the composition are a compound ofFormula (I), (I-1), (II), (III), (IV), (V), (VI), (VII), (VIII), (IX),or a salt thereof.

In certain embodiments, a compound, such as a compound of Formula (I),(I-1), (II), (III), (IV), (V), (VI), (VII), (VIII), (IX), or a saltthereof is included as an additive to animal feed or drinking water foranimals. In certain embodiments, the compound is formulated intopremixes in various potencies from 1 to 10% by weight.

The compositions for use either as feed additives or as directlyadministered preparations may contain any convenient proportion of thecompound, for example from 1% or less to 90% or more, by weight. Liquidformulations typically contain 50 to 90% by weight, whereas solidformulations typically contain 1 to 25% by weight.

In one aspect, the methods described herein include providing a compoundof Formula (I), (I-1), (II), (III), (IV), (V), (VI), (VII), (VIII), or(IX) to a subject via a prodrug. Thus, in certain embodiments, a prodrugis administered to a subject to provide a metabolite that inhibitsgrowth of a filarial worm, sterilizes an adult filarial worm, reducesmicrofilariae load, kills a filarial worm, inhibits growth of bacteriaassociated with a filarial worm, and/or kills bacteria associated with afilarial worm. In this way, filarial worms and/or bacteria harboredwithin worms are contacted with the metabolite. Contemplated metabolitesinclude one or more compounds of Formula (I), (I-1), (II), (III), (IV),(V), (VI), (VII), (VIII), or (IX). Exemplary prodrug forms of thecompounds described herein include 4′-modified prodrugs, such ascompounds having a 4′″-O-acyl moiety (e.g., a 4′″-O-acetyl,4′″-O-propionyl, or 4′″-O-methylpropionyl moiety.

The compounds, compositions, and methods described herein will be betterunderstood by reference to the following examples, which are included asan illustration of and not a limitation upon the scope of the invention.

F. EXEMPLARY EMBODIMENTS

In one aspect, the present invention includes embodiments enumerated inthe following subparagraphs:

A1. A method of preventing or treating filariasis in a subject in needthereof, comprising administering to the subject a therapeuticallyeffective amount of a macrolide antibiotic.

A2. The method of embodiment A1, wherein the macrolide antibiotic istylosin A or a salt thereof.

A3. The method of embodiment A1, wherein the macrolide antibiotic istylosin tartrate.

A4. The method of embodiment A1, wherein the macrolide antibiotic is aderivative or analog of tylosin A or a salt thereof.

A5. The method of any one of the preceding embodiments, wherein thefilariasis is lymphatic filariasis or subcutaneous filariasis.

A6. The method of any one of the preceding embodiments, wherein thefilariasis is caused by Onchocerca volvulus, Wuchereria bancrofti,Brugia malayi, Brugia timori, or Dirofilaria immitis.

A7. The method of any one of the preceding embodiments, wherein thesubject is a human.

In one aspect, the present invention includes embodiments enumerated inthe following subparagraphs:

B8. A method of preventing or treating filariasis in a subject in needthereof, comprising providing to the subject a therapeutically effectiveamount of a compound of Formula (I-1):

or a salt thereof, wherein:

R₁ represents hydrogen or —C(O)R₃, wherein R₃ represents C₁-C₆-alkyl;and

R₂ represents —C(O)C(R₄)(R₅)(R₆), wherein each of R₄, R₅, and R₆ areindependently selected from the group consisting of hydrogen,C₁-C₆-alkyl, C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl,heterocycloalkyl, arylalkyl, heteroarylalkyl, andC₃-C₈-cycloalkyl-C₁-C₄-alkyl; or

R₂ represents —C(O)N(R₇)(R₈), wherein each of R₇ and R₈ areindependently selected from the group consisting of C₁-C₆-alkyl,C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl, heterocycloalkyl,arylalkyl, heteroarylalkyl, and C₃-C₈-cycloalkyl-C₁-C₄-alkyl, or R₇ andR₈ together with the nitrogen atom to which they are attached form anoptionally substituted saturated or partially saturated heterocyclicring; or

R₂ represents —CH₂-A₁, wherein A₁ represents a 6- to 10-membered aryl ora 5- to 10-membered heteroaryl and A₁ is unsubstituted or substitutedwith one or more R_(A), wherein each R_(A) is independently selectedfrom the group consisting of halogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, and—O—R₉, where R₉ represents C₁-C₆-alkyl; and

each of a and b independently represents either a single bond or adouble bond.

B9. The method of embodiment B8, wherein R₁ is hydrogen.

B10. The method of embodiment B8, wherein R₁ is —C(O)R₃.

B11. The method of embodiment B10, wherein R₃ is methyl, isopropyl, orn-butyl.

B12. The method of any one of the preceding embodiments, wherein R₂ is—C(O)C(R₄)(R₅)(R₆) and R₄ is C₁-C₆-alkyl.

B13. The method of any one of the preceding embodiments, wherein R₂ is—C(O)C(R₄)(R₅)(R₆) and each of R₄, R₅, and R₆ are C₁-C₆-alkyl.

B14. The method of any one of embodiments B8-B11, wherein R₂ is—C(O)N(R₇)(R₈) and each of R₇ and R₈ are C₁-C₆-alkyl, aryl, orC₃-C₈-cycloalkyl.

B15. The method of any one of embodiments B8-B11, wherein R₂ is—C(O)N(R₇)(R₈) and R₇ and R₈ together with the nitrogen atom to whichthey are attached form an optionally substituted saturated or partiallysaturated heterocyclic ring.

B16. The method of embodiment B15, wherein the heterocyclic ring is apyrrolidine, a piperidine, an azepane, or a morpholine.

B17. The method of any one of embodiments B8-B11, wherein R₂ is —CH₂-A₁and A₁ is an unsubstituted phenyl or a phenyl substituted with one ormore R_(A).

B18. The method of embodiment B17, wherein R_(A) is halogen.

B19. The method of embodiment B17, wherein R_(A) is —O—R₉.

B20. The method of any one of embodiments B8-B19, wherein at least oneof a and b represents a single bond and the other of a and bindependently represents either a single bond or a double bond.

B21. The method of any one of embodiments B8-B19, wherein both a and brepresent a single bond.

B22. The method of any one of embodiments B8-B19, wherein both a and brepresent a double bond.

B23. The method of embodiment B8, wherein at least one of a and brepresents a single bond and the other of a and b independentlyrepresents either a single bond or a double bond.

B24. The method of embodiment B8, wherein both a and b represent asingle bond.

B25. The method of embodiment B8, wherein both a and b represent adouble bond.

B26. The method of any one of embodiments B23-B25, wherein

R₁ is —C(O)CH₃ and R₂ is

R₁ is —C(O)CH₃ and R₂ is

R₁ is —C(O)CH₃ and R₂ is

R₁ is —C(O)CH₃ and R₂ is

R₁ is —C(O)CH(CH₃)₂ and R₂ is

R₁ is —C(O)CH(CH₃)₂ and R₂ is

R₁ is —C(O)CH(CH₃)₂ and R₂ is

R₁ is —C(O)CH(CH₃)₂ and R₂ is

R₁ is —C(O)CH(CH₃)₂ and R₂ is

R₁ is hydrogen and R₂ is

R₁ is —C(O)(CH₂)₃CH₃ and R₂ is

R₁ is —C(O)CH₃ and R₂ is —C(O)C(CH₃)₃;

R₁ is —C(O)CH(CH₃)₂ and R₂ is —C(O)C(CH₃)₃;

R₁ is hydrogen and R₂ is —C(O)C(CH₃)₃;

R₁ is —C(O)CH₃ and R₂ is —C(O)N(CH₂CH₃)₂;

R₁ is —C(O)CH₃ and R₂ is —C(O)N(CH₃)(C₆H₅);

R₁ is —C(O)CH₃ and R₂ is

R₁ is —C(O)CH(CH₃)₂ and R₂ is —C(O)N(CH₂CH₃)₂;

R₁ is hydrogen and R₂ is —C(O)N(CH₂CH₃)₂;

R₁ is —C(O)CH₃ and R₂ is

R₁ is —C(O)CH₃ and R₂ is

R₁ is —C(O)CH₃ and R₂ is —C(O)N(CH(CH₃)₂)₂;

R₁ is —C(O)CH₃ and R₂ is —C(O)N((CH₂)₃CH₃)₂;

R₁ is —C(O)CH₃ and R₂ is —C(O)N((CH₂CHCH₃)₂)₂;

R₁ is —C(O)CH₃ and R₂ is

R₁ is —C(O)CH₃ and R₂ is

R₁ is —C(O)CH(CH₃)₂ and R₂ is —C(O)N(CH₃)₂;

R₁ is —C(O)CH(CH₃)₂ and R₂ is —C(O)N(CH₂CH₃)((CH₂)₃CH₃);

R₁ is hydrogen and R₂ is —C(O)N(CH(CH₃)₂)₂;

R₁ is hydrogen and R₂ is —C(O)N((CH₂)₃CH₃)₂;

R₁ is H and R₂ is

R₁ is —C(O)CH(CH₃)₂ and R₂ is

R₁ is —C(O)CH₃ and R₂ is

R₁ is —C(O)(CH₂)₃(CH₃) and R₂ is

R₁ is —C(O)(CH₂)₃(CH₃) and R₂ is

R₁ is hydrogen and R₂ is

R₁ is hydrogen and R₂ is

R₁ is hydrogen and R₂ is

or

R₁ is hydrogen and R₂ is

B27. The method of any one of embodiments B8-B26, wherein a compound ofFormula (I-1) is administered to the subject.

B28. The method of any one of embodiments B8-B26, wherein a prodrug of acompound of Formula (I-1) is administered to the subject.

G. EXAMPLES Example 1 In Vitro Assay

A C6/36 Aedes albopictus cell line infected with Wolbachia pipientis(Wolbachia strain wAlbB) derived from Aa23 A. albopictus cell line(O'Neill et al., 1997; Insect Mol Biol; Turner et al., (2006) J.Immunol. 7:1240-1249) was used to screen compounds. Cells were culturedin Leibovitz's L15 +L-glutamine supplemented with heat-inactivatedFoetal Calf Serum (HI-FCS), non-essential amino acids and tryptosephosphate broth. Culture medium was filter-sterilized through a 0.2 μmfilter and stored at 4° C. Compounds were provided as 10 mM stocks inDMSO, diluted to 50 μM working stock to give final concentration of 5 μMon the test plate. Concentrated stocks were frozen at −20° C.

Prior to use in the screening assay, cell cultures were sub-passaged (6days prior) to provide ˜90% confluent cells on Day 0 of screening assay.On Day 0 (assay set-up), the medium was removed from the stock cultureflask and replaced with fresh medium. The cells were detached byscraping and cell density was calculated using an automated cellcounter. The cells were then diluted at working density and aliquoted at90 μl to each well of a Cell Carrier 384 well plate (Perkin Elmer). Cellplates were incubated at 26° C.

Control solution (DMSO-medium) was dispensed at 10 μl per well for“untreated” wells. Test solution (Drug-DMSO) was also dispensed at 10 μl(from working plate) per well for “treated” wells. The plates wereincubated at 26° C., inside plastic wallet in incubator, for 7 days.

On Day 7, 25 μl of staining medium/dye (SYTO 11, Life Technologies) wasadded to each sample well and allowed to stain for 15 minutes in thedark. All the medium was removed from each sample well withoutdisturbing the cells and replaced with 100 μl of fresh medium. Plateswere imaged on the Operetta High Content Imaging system (Perkin Elmer)and analyzed using texture analysis through Harmony software (PerkinElmer). The cell-based screen and analysis are described in detail inClare et al. (2014) J Biomol Screen.

Tylosin A, Tylosin B, and Compounds 1-39 having structures as shown inTable 1A were tested for anti-Wolbachia activity:

TABLE 1A Com- EC₅₀ pound R₁ R₂ (nM) Tylo- 36/24/26 sin A Tylo- 88 sin B 1 C(O)CH₃

0.6  2 C(O)CH₃

6.2  3 C(O)CH₃

1.1  4 C(O)CH₃

6.5  5 C(O)CH(CH₃)₂

13  6 C(O)CH(CH₃)₂

25  7 C(O)CH(CH₃)₂

29  8 C(O)CH(CH₃)₂

29  9 C(O)CH(CH₃)₂

181 10 H

<0.1 11 C(O)(CH₂)₃CH₃

44 12 C(O)CH₃ C(O)C(CH₃)₃ 7.5 13 C(O)CH(CH₃)₂ C(O)C(CH₃)₃ 33 14 HC(O)C(CH₃)₃ 0.85 15 C(O)CH₃ C(O)N(CH₂CH₃)₂ <1 16 C(O)CH₃C(O)N(CH₃)(C₆H₅) 15 17 C(O)CH₃

27 18 C(O)CH(CH₃)₂ C(O)N(CH₂CH₃)₂ 25 19 H C(O)N(CH₂CH₃)₂ 1.6 20 C(O)CH₃

46 21 C(O)CH₃

2.4 22 C(O)CH₃ C(O)N(CH(CH₃)₂)₂ 269 23 C(O)CH₃ C(O)N((CH₂)₃CH₃)₂ 331 24C(O)CH₃ C(O)N(CH₂CH(CH₃)₂)₂ 358 25 C(O)CH₃

15 26 C(O)CH₃

1,700 27 C(O)CH(CH₃)₂ C(O)N(CH₃)₂ 33 28 C(O)CH(CH₃)₂C(O)N(CH₂CH₃)((CH₂)₃CH₃) 282 29 H C(O)N(CH(CH₃)₂)₂ 18 30 HC(O)N((CH₂)₃CH₃)₂ 13 31 H

1,140 32 C(O)CH(CH₃)₂

11 33 C(O)CH₃

4.42 34 C(O)(CH₂)₃(CH₃)

<10 35 C(O)(CH₂)₃(CH₃)

98 36 H

3 37 H

<3 38 H

<0.1 39 H

<0.1

Compounds 40-43 having structures as shown in Table 1B were tested foranti-Wolbachia activity:

TABLE 1B Compound R₁ R₂ EC₅₀ (nM) 40 H C(O)N(CH₂CH₃)₂ 25 41 C(O)CH(CH₃)₂C(O)N(CH₂CH₃)₂ 81 42 H

10 43 H

565

Compounds 44-55 having structures as shown in Table 1C were tested foranti-Wolbachia activity:

TABLE 1C Compound R₁ R₂ R₁₀ EC₅₀ (nM) 44 C(O)CH₃ C(O)N(CH₂CH₃)₂C(O)CH₂CH₃ 3.50 45 H C(O)N(CH₂CH₃)₂ C(O)CH₂CH₃ 0.13 46 C(O)CH₂CH₃C(O)N(CH₂CH₃)₂ C(O)CH₂CH₃ 2.93 47 C(O)CH₃

C(O)CH₂CH₃ 1.79 48 H

C(O)CH₂CH₃ 0.41 49 C(O)CH₃ C(O)N(CH₂CH₃)₂ C(O)CH₃ 0.42 50 HC(O)N(CH₂CH₃)₂ C(O)CH₃ 0.25 51 H C(O)N(CH₂CH₃)₂ C(O)CH(CH₃)₂ 3.03 52C(O)CH₃

C(O)CH₃ 0.13 53 H

C(O)CH₃ 0.22 54 C(O)CH₃

C(O)CH(CH₃)₂ 3.03 55 H

C(O)CH(CH₃)₂ 0.13

Example 2 Larval Litomosoides sigmodontis mouse model

In this mouse model of filariasis (Hoerauf A, et al. (1999) Journal ofClinical Investigation 103(1):11-18), BALB/c mice (6-8 week old) wereinfected via natural larvae transmission, through the bite of infectedtropical mites (Ornithonyssus bacoti), and treatment started on the dayfollowing infection. Anti-Wolbachia efficacy was measured byquantitative PCR analysis, using genomic DNA extracted from larvae, ofthe Wolbachia ftsZ gene, and expressed as a reduction in Wolbachia loadin comparison to the vehicle control group. In the Litomosoidessigmodontis larval model, 7 days treatment with Tylosin A lead toWolbachia reductions of 91.7% and 21.9%, with parenteral and oraldosing, respectively. Doxycycline treatment (50 mg/kg/day for 14 days)lead to a 99.9% Wolbachia reduction. Thus, tylosin A effectively clearedWolbachia from filarial larvae (Litomosoides sigmodontis) in a mousemodel of filariasis when delivered parenterally (intraperitoneally), toa similar extent to doxycycline, with a shorter dosing regimen.

Example 3 Larval Brugia malayi Mouse Model

In a larval Brugia malayi mouse model treatment groups (BALB/c IL4Rα−/−mice, 6-8 week old) received compounds by oral delivery for 7 to 14 dayscommencing on the day of intraperitoneal infection with Brugia malayithird-stage larvae. At 14 days post-infection, larvae were recoveredfrom the peritoneal cavity, counted, and length measured. Genomic DNAwas extracted from individual worms (10/group) and quantification of theWolbachia surface protein (wBm-wsp) gene copy numbers performed byquantitative PCR.

Table 2 shows Wolbachia reductions in Brugia malayi larval infectionmouse model (% compared to median vehicle control) following treatmentwith tylosin A (“TYL A”), Compound 18, or Compound 19. Treatment dose(mg/kg) shown in parentheses and duration stated in days (d).Abbreviations: DOX (doxycycline), bid (twice daily), qd (once daily), PO(oral), IP (parenteral). Data in Table 2 are expressed as a reduction inWolbachia load in comparison to the vehicle control group.

TABLE 2 Treatment (mg/kg) % Wolbachia reduction DOX (50 qd) PO 7 d 88.7%DOX (50 qd) PO 14 d 98.3% TYL A (50 qd) IP 14 d 99.9% TYL A (50 qd) PO14 d 50.4% Compound 19 (50 qd) PO 7 d 99.8% Compound 19 (50 qd) PO 14 d99.9% Compound 19 (25 qd) PO 14 d 99.8% Compound 18 (50 qd) PO 7 d 98.0%Compound 18 (50 qd) PO 14 d 99.6% Compound 18 (25 qd) PO 14 d 81.8%

In this larval model, Compound 19 reduced the Wolbachia load by 99.9% attwo weeks post-infection, when dosed once daily (qd) at 50 mg/kg/dayorally for 14 days. At a lower dose of 25 mg/kg/day, the Wolbachia loadwas also reduced by 99.8%. Both results are superior to doxycyclinegiven at 50 mg/kg/day for 14 days (98.3% reduction). When Compound 19was given at 50 mg/kg/day for 7 days, Wolbachia load was still reducedby 99.8% (Table 2). Tylosin A (50 mg/kg/day) showed comparableanti-Wolbachia efficacy when dosed intraperitoneally for 14 days (99.9%)but was not sufficiently effective when dosed orally (50.4%) (Table 2).

Additional compounds were tested in the larval mouse model of filarialdisease at both 25 and 50 mg/kg/day for 7 days (Table 3). Table 3 showsWolbachia reductions in Brugia malayi larval infection mouse model (%compared to median vehicle control) following oral treatment withcompounds disclosed herein. Treatment dose (mg/kg) shown in parenthesesand duration stated in days (d). Abbreviations: DOX (doxycycline), qd(once daily).

TABLE 3 Weighted exposure % Wolbachia Treatment (mg/kg) ng-hr/mL/nMreduction DOX (50 qd) 7 d ND 77.4% DOX (50 qd) 14 d ND 99.3% Compound 19(25 qd) 7 d 5,400 99.4% Compound 19 (50 qd) 7 d 15,000 99.6% Compound 10(25 qd) 7 d 900 97.9% Compound 10 (50 qd) 7 d 13,500 99.5% Compound 37(25 qd) 7 d 1,200 73.6% Compound 37 (50 qd) 7 d 4,000 91.3% Compound 18(25 qd) 7 d 240 54.3% Compound 18 (50 qd) 7 d 700 98.2% Compound 8 (25qd) 7 d 27   0% Compound 8 (50 qd) 7 d 97   0% Compound 34 (25 qd) 7 d1,220 43.5% Compound 34 (50 qd) 7 d 5,700 93.9%

Compound 10 reduced the Wolbachia load by 99.5% at two weekspost-infection, when dosed at 50 mg/kg/day orally for 7 days. At a lowerdose of 25 mg/kg/day, the Wolbachia load was reduced by 97.9%. Thesereductions compare with the corresponding values for Compound 19 (99.6%and 99.4%, respectively) in this study. All results are superior todoxycycline given at 50 mg/kg/day for 7 days (77.4% reduction); all butthe lower dose of Compound 10 are comparable or superior to doxycycline50 mg/kg/day for 14 days (99.3% reduction). Thus, compounds disclosedherein appear to offer both improved efficacy and the potential for ashorter course of treatment over both tetracycline and doxycycline.

Example 4 Adult Brugia malayi Mouse Model

In an adult Brugia malayi mouse model treatment groups (BALB/cCCR3−/−mice, 6-8 week old) received compounds by oral delivery for 7-28days beginning at 6-10 weeks post-infection intraperitoneal with Brugiamalayi third-stage larvae. Following treatment, at 12 weekspost-infection, adult worms and released microfilariae were recoveredfrom the peritoneal cavity, counted and staged for sex. Genomic DNA wasextracted from individual adult worms (10/group) and quantification ofthe Wolbachia surface protein (wBm-wsp) performed by quantitative PCR.

Table 4 shows Wolbachia reductions in Brugia malayi adult infectionmodel (% reduction compared to median vehicle control) following oraltreatment with tylosin A (“TYL A”) and Compound 19. Treatment dose(mg/kg/day) shown in parentheses and duration stated in days (d). MIN(minocycline), bid (twice daily), qd (once daily). Data in Table 4 areexpressed as a reduction in Wolbachia load in comparison to the vehiclecontrol group.

TABLE 4 Treatment (mg/kg) % Wolbachia reduction MIN (25 bid) 28 d 83.8%TYL A (50 qd) 14 d   0% Compound 19 (50 qd) 7 d 43.1% Compound 19 (50qd) 14 d 73.4%

Compound 19 was tested in the adult Brugia malayi mouse model and waseffective against Wolbachia (Table 4). Compound 19 given for 14 days at50 mg/kg/day orally decreased Wolbachia load by 73.4% in this model, andthus is comparable to the tetracycline, minocycline, given at the samedose (25 mg/kg twice a day) for a duration of 28 days (83.8%). In aseparate study using this adult Brugia malayi mouse model, it has beendetermined that minocycline is superior to doxycycline, dose-for-dose.Adult worm recoveries did not vary significantly between Compound 19treatment and control groups. Again, this result suggests that compoundsdisclosed herein may provide clinical benefit with a shorter dosingregimen. PK samples were taken at selected time points during day 1 andday 7 following dosing with Compound 19 (50 mg/kg/day) and the PKprofiles showed an increase in the circulating concentrations ofCompound 19 after multiple dosing.

A dose escalation study of Compound 19 showed that both 150 and 250mg/kg daily oral treatment resulted in a >90% Wolbachia reduction (Table5), and that the higher dose treatment (250 mg/kg/day) can reduce thetreatment time to 7 days in order to achieve >90% Wolbachia reduction inadult female worms (98.3% reduction) (Table 5). This demonstratescomparable anti-Wolbachia efficacy of Compound 19 to a minocyclinetreatment regimen of 25 mg/kg bid for 28 days. Thus, compounds disclosedherein may allow for a reduced treatment duration and, in particular,may be suitable for a treatment period of 7 days or less.

Table 5 shows Wolbachia reductions in Brugia malayi adult infectionmouse model (% reduction compared to median vehicle control) followingoral treatment with Compound 19 in a dose escalation study. Treatmentdose (mg/kg/day) shown in parentheses and duration stated in days (d).MIN (minocycline), bid (twice daily), qd (once daily).

TABLE 5 Treatment (mg/kg) % Wolbachia reduction MIN (25 bid) 28 d 95.5%Compound 19 (150 qd) 14 d 90.0% Compound 19 (250 qd) 14 d 96.8% Compound19 (250 qd) 7 d 98.3%

Example 5 Adult Brugia malayi Jird Model

In this model of adult filarial (macrofilariae) infection, Mongolianjirds (Meriones unguiculatus) were infected intraperitoneally withBrugia malayi third-stage larvae (Ash and Riley, (1970) J Parasitol.56(5):969-73). Infected jirds were treated at +12-20 weekspost-infection for periods up to 6 weeks. Jirds were necropsied for wormrecoveries. Adult worms were staged for sex and motile releasedmicrofilariae were counted. Genomic DNA was extracted from individualworms (10/group) and quantification of the Wolbachia surface protein(wBm-wsp) and Brugia malayi glutathione S-transferase (Bm-gst) gene copynumbers performed by quantitative PCR, and expressed as a reduction inWolbachia load in comparison to the vehicle control group.

Treatment with Compound 10 in the adult Brugia malayi jird model showedthat treatment with both 10 and 50 mg/kg daily oral treatment for 14days resulted in a >90% Wolbachia reduction (Table 6).

Table 6 shows Wolbachia reductions in Brugia malayi adult infection jirdmodel (% reduction compared to median vehicle control) following oraltreatment with Compound 10. Treatment dose (mg/kg/day) shown inparentheses and duration stated in days (d). DOX (doxycycline), qd (oncedaily).

TABLE 6 Treatment (mg/kg) % Wolbachia reduction DOX (200 qd) 21 d 99.1%Compound 10 (10 qd) 14 d 99.4% Compound 10 (50 qd) 14 d 99.8%

These results demonstrate that compounds disclosed herein, administeredfor a reduced treatment duration, have comparable anti-Wolbachiaefficacy to doxycycline treatment of 200 mg/kg/day for 21 days.

Table 7 shows reductions in motile peritoneal microfilariae load inBrugia malayi adult infection jird model (% reduction compared to medianvehicle control) following oral treatment with Compound 10. Treatmentdose (mg/kg/day) shown in parentheses and duration stated in days (d).DOX (doxycycline), qd (once daily).

TABLE 7 Treatment (mg/kg) % reduction in microfilariae DOX (200 qd) 21 d90.5% Compound 10 (10 qd) 14 d 70.1% Compound 10 (50 qd) 14 d 99.6%

In addition to its anti-Wolbachia efficacy, treatment with Compound 10in the adult Brugia malayi jird model lead to a reduction in motileperitoneal microfilariae load (Table 7). Compound 10 showed adose-dependent reduction in motile microfilariae recovered from theperitoneum, 70.1% and 99.6% reduction with 10 and 50 mg/kg daily oraltreatment, respectively.

Thus, compounds disclosed herein are effective against Wolbachia inpreclinical models of filarial brugian lymphatic filariasis worminfection. Moreover, compounds disclosed herein offer the potential fora shorter course of treatment over the standard of care withtetracycline or doxycycline.

Example 6 Adult Onchocerca ochengi Mouse Model

In this model, adult male Onchocerca ochengi (closest relative speciesto the human parasite causing river blindness, Onchocerca volvulus) arederived from cattle natural hosts and surgically implanted into theperitoneal cavity of CB.17 SCID (BALB/c congenic) mice under anaesthesia(Halliday et al Parasit. Vectors 2014 7:472). After 3 days followingsurgery, mice were treated by oral gavage for periods up to 4 weeks.Mice were necropsied for worm recoveries 6 weeks after start oftreatment. Genomic DNA was extracted from individual worms (n=10/group)and quantification of the Wolbachia surface protein (wBm-wsp) andOnchocerca glutathione S-transferase (Ov-gst) gene copy numbersperformed by quantitative PCR. Data is expressed as a reduction inWolbachia:gst ratios in comparison to the vehicle control group.

Table 8 shows reductions in Wolbachia load in Onchocerca ochengi adultmale mouse model (% reduction compared to median vehicle control)following oral treatment with Compound 10 and Compound 19. Treatmentdose (mg/kg/day) shown in parentheses and duration stated in days (d).DOX (doxycycline), qd (once daily) bid (twice daily).

TABLE 8 Treatment (mg/kg) % Wolbachia reduction DOX (25 bid) 28 d 99.8%MIN (25 bid) 28 d 99.7% Compound 19 (250 qd) 14 d 99.7% Compound 10 (75qd) 07 d 97.2%

Both Compound 10 and Compound 19 mediated a superior effect to thetetracyclines, DOX and MIN, by reducing Wolbachia loads in adult maleOnchocerca beyond 90% in a shortened dose timeframe. Compound 19 reducedWolbachia by 99.7% following 14 days dosing at 250 mg/kg (qd). Compound10 reduced Wolbachia by 97.2% following 07 days dosing at 75 mg/kg (qd).

Thus, compounds disclosed herein are effective against Wolbachia in apreclinical model of onchocerciasis worm infection. Moreover, compoundsdisclosed herein offer the potential for a shorter course of treatmentover the standard of care with doxycycline or minocycline.

Example 7 Loa loa Microfilariae Ex Vivo Counter-Screen

This ex vivo assay is used to assess direct Loa loa microfilaricidaleffects of drug compounds. Bloodborne Loa loa microfilariae aregenerated from experimental infections of splenectomised baboons withthe human stain of L. loa (Orihel et al, Trop Med Parasitol, 1985. 36:p.215). L. loa microfilariae were purified from venous blood samples byPercoll gradient centrifugation. Loa loa microfilariae were adjusted toa density of 0.5×10⁴/ml and plated into 96-well plates in Dulbecco'sModified Eagle Medium (DMEM) containing 10% Foetal Calf Serum (FCS).Triplicate wells of Loa loa microfilariae were exposed to eitherivermectin (64 μg/ml: positive control), compound 10 (0.018 and 0.18μg/ml), compound 19 (0.11 and 1.11 μg/ml) or 0.1% DMSO vehicle control.Dose levels of compound 10 and compound 19 were matched to predictiveC_(max) and 10× C_(max) human plasma concentrations based on PK-PDmodeling. L. loa were cultured at 37° C./5% CO₂ for +7 days andmonitored daily with a semi-quantitative score applied to individual mfmotility.

Table 9 shows changes in L. loa microfilariae motility at indiciatedtime-points (days) compared with baseline in cultures treated withvehicle solvent only (VC), ivermectin (IVM), compound 10 or compound 19.

TABLE 9 Exposure Motility Survival Treatment (μg/ml) time (days) (mean %vs baseline) (%) VC (—) 2 98.27 100 7 80.91 100 IVM (64) 2 5.71 100 7 00 Cmpd 10 (0.018/0.18) 2 98.01/98.06 100 7 84.31/84.71 100 Cmpd19(0.11/1.1) 2 97.54/99.24 100 7 86.56/84.77 100

Both compound 10 and compound 19 showed no effect in cessatingmicrofilariae motility compared with IVM, which rendered microfilariaecompletely immotile after a period of 7 days. Further, both compound 10and compound 19 did not alter degree of motility compared with VC at +2or +7 days in contrast to IVM which induced >90% reduction in motilityin +2 days.

Thus, compounds disclosed herein are ineffective against Loa loamicrofilariae in an ex vivo assay of microfilaricidal assessment. Thisindicates the compounds disclosed herein offer the potential for safetreatment of patients co-infected with loaisis and onchocerciasis orlymphatic filariasis.

Example 8 Compounds Having Structures as Shown in Tables 1A, 1B, and 1Cwere Prepared as Described Below

Compound A. Tylosin A 2′-OAc

Using a modification of the procedures described in Tsuchiya et al, JAntibiotics 1982, (35), 661, tylosin A tartrate (5 mmol) was dissolvedin 20 mL of ethanol; acetic anhydride (0.66 mL, 1.5 equivalents) wasadded and the resultant solution was stirred at 40° C. for four hours.Reaction was quenched by addition of 20 mL of aqueous sodiumbicarbonate; the mixture was stirred for 30 minutes, then poured into aseparatory funnel and the organic layer was removed. The aqueous layerwas extracted twice with 10 mL of chloroform. The combined organiclayers were washed with brine and dried over Na₂SO₄. The crude productwas carried forward without further purification.

Compound B Tylosin A 2′-OiBu

Compound B was prepared using procedure for the preparation of CompoundA, except for substituting isobutyric anhydride (3.0 equivalents) foracetic anhydride, and using chloroform as solvent.

Compound C Tylosin A 2′-OAc, 3″/4″ Dibutyl Tin Reagent

Using a modification of the procedures described in Kiyoshima et al.,Chem. Pharm. Bull. 1989, 37(4), 861, Compound A (10 mmol) was dissolvedin 150 mL of toluene; followed by the addition of 7.5 g (3.0equivalents) of dibutyltin oxide. The resultant mixture was stirred atreflux (bath temperature 115° C.) for 30 minutes. A still head was addedand the bath temperature was raised to 130° C., distilling off solventsto a final volume of about 60 mL. The resultant solution was used forfurther reactions without additional purification.

Compound D Tylosin A 2′-OiBu, 3″/4″ Dibutyl Tin Reagent

Using a modification of the procedures described in Kiyoshima et al.,Chem. Pharm. Bull. 1989, 37(4), 861, Compound B (10 mmol) was dissolvedin 150 mL of toluene; followed by the addition of 7.5 g (3.0equivalents) of dibutyltin oxide. The resultant mixture was stirred atreflux (bath temperature 115° C.) for 30 minutes. A still head was addedand the bath temperature was raised to 130° C., distilling off solventsto a final volume of about 60 mL. The resultant solution was used forfurther reactions without additional purification.

Compound E. Tylosin A 2′-OVal

Using a modification of the procedures described in Tsuchiya et al, JAntibiotics 1982, (35), 661, tylosin A tartrate (3 mmol) was dissolvedin 15 mL of chloroform; valeric anhydride (0.89 mL, 1.5 equivalents) wasadded and the resultant solution was stirred at ambient temperature for41 hours. Reaction was quenched by addition of 5 mL of aqueous sodiumbicarbonate; the mixture was stirred for 30 minutes, then poured into aseparatory funnel and the organic layer was removed. The aqueous layerwas extracted with 5 mL of chloroform. The combined organic layers werewashed with brine and dried over Na₂SO₄. The crude product was carriedforward without further purification.

Compound F Tylosin A 2′-OVal, 3″/4″ Dibutyl Tin Reagent

Using a modification of the procedures described in Kiyoshima et al.,Chem. Pharm. Bull. 1989, 37(4), 861, Compound E (3 mmol) was dissolvedin 50 mL of toluene; followed by the addition of 2.24 g (3.0equivalents) of dibutyltin oxide. The resultant mixture was stirred atreflux (bath temperature 115° C.) for 30 minutes. A still head was addedand the bath temperature was raised to 130° C., distilling off solventsto a final volume of about 20 mL. The resultant solution was used forfurther reactions without additional purification.

Compound G 10,11,12,13-tetrahydro-Tylosin A

The title compound was prepared according to the procedure of Narandjaet al., J. Antibiotics 1995, 48930, 248.

Compound H 2′-OAc, 10,11,12,13-tetrahydro-Tylosin A

Compound G (1.53 g) was dissolved in 10 mL of ethanol; 0.25 mL of aceticanhydride was added, and the resultant solution was stirred at 40° C.for 2 hours. The solution was concentrated in vacuo; the residue wastaken up in chloroform and stirred with aqueous sodium bicarbonatesolution for ten minutes. The mixture was poured into a separatoryfunnel; the organic layer was removed and the aqueous layer wasextracted with chloroform. The combined organic layers were dried oversolid sodium sulfate, filtered and concentrated in vacuo to give thetitle compound.

Compound J 2′-OAc, 10,11,12,13-tetrahydro-Tylosin A, Tin Reagent

Using a modification of the procedures described in Kiyoshima et al.,Chem. Pharm. Bull. 1989, 37(4), 861, Compound J (1.60 g) was dissolvedin 25 mL of toluene; followed by the addition of 0.62 g (1.5equivalents) of dibutyltin oxide. The resultant mixture was stirred atreflux (bath temperature 115° C.) for 30 minutes. A still head was addedand the bath temperature was raised to 140° C., distilling off solventsto a final volume of about 10 mL. The resultant solution was used forfurther reactions without additional purification.

Compound 1

Compound C (1 mmol) in 6 mL toluene solution, was combined with benzylbromide (1.5 equivalents) and 20 mg of tetra-n-butylammonium iodide. Theresultant mixture was heated at 90° C. for 2 days. Reaction was quenchedwith aqueous sodium bicarbonate and stirred for ten minutes. The layerswere separated and the organic layer was washed with brine. Combinedaqueous layer was extracted with chloroform. Combined organic layerswere dried over Na₂SO₄, filtered, and concentrated. The residue waschromatographed on a 50 g silica gel column, eluting with a gradientfrom 1:1 ethyl acetate/hexanes to 100% ethyl acetate. The title compoundwas collected as a white solid.

Compound 2

Compound 2 was prepared using the procedure for the preparation ofCompound 1, except for substituting 4-trifluoromethylbenzyl bromide forbenzyl bromide. The crude product was purified by HPLC on a WatersSunfire C8 column, eluting with a gradient of 35%/50%/87%/100% methanolin 0.1% ammonium acetate.

Compound 3

Compound C (1.25 mmol) in 20 mL toluene solution, was combined with4-fluorobenzyl bromide (2.0 equivalents) and 200 mg oftetra-n-butylammonium iodide. The resultant mixture was heated at 90° C.for 2 days. The reaction mixture was concentrated in vacuo; the residuewas chromatographed on a 50 g silica gel column, eluting with a gradientfrom 20% ethyl acetate/hexanes to 100% ethyl acetate, producing thetitle compound.

Compound 4

Compound 4 was prepared using the procedure for the preparation ofCompound 1, except for substituting 4-chlorobenzyl bromide for benzylbromide. The crude product was purified by HPLC on a Waters Sunfire C8column, eluting with a gradient of 35%/50%/87%/100% methanol in 0.1%ammonium acetate.

Compound 5

Compound 5 was prepared using the procedure for the preparation ofCompound 1, except for substituting Compound D for Compound C. The crudeproduct was purified by chromatography on a silica gel column, elutingwith a gradient from 20% ethyl acetate/hexanes to 100% ethyl acetate.

Compound 6

Compound D (1.5 mmol) in 10 mL toluene solution, was combined with2,4-difluorobenzyl bromide (2.5 equivalents) and 20 mg oftetra-n-butylammonium iodide. The resultant mixture was heated at 90° C.for 3 days. The solvents were removed in vacuo; the residue waschromatographed on a 50 g silica gel column, eluting with a gradientfrom 1:1 ethyl acetate/hexanes to 100% ethyl acetate, to produce thetitle compound.

Compound 7

Compound 7 was prepared using the procedure for the preparation ofCompound 1, except for substituting Compound D for Compound C, andsubstituting 2-bromomethyl benzothiazole for benzyl bromide. The crudeproduct was purified by HPLC on a Waters Sunfire C8 column, eluting witha gradient of 20%/60%/100% methanol in 0.1% ammonium acetate.

Compound 8

Compound D (4.7 mmol) in 20 m L of toluene, was combined with4-fluorobenzyl bromide (2.0 eq) and 200 mg of tetra-n-butylammoniumiodide. The resultant mixture was warmed at 90° C. for 60 hours.Solvents were removed in vacuo; the residue was chromatographed on a 100g silica gel column, eluting with a gradient from 20% ethylacetate/hexanes to 100% ethyl acetate, giving the title compound.

Compound 9

Compound 9 was prepared using the procedure for the preparation ofCompound 1, except for substituting Compound D for Compound C, andsubstituting 1-naphthylmethyl bromide for benzyl bromide. The crudeproduct was chromatographed on a 10 g silica column, eluting with agradient from 20% ethyl acetate/hexanes to 100% ethyl acetate.

Compound 10

Compound 3 (5.0 mmol) was dissolved in 80 mL of methanol; 50 mg of solidsodium bicarbonate was added, and the resultant mixture was stirred atambient temperature for 5 days. Solvents were removed in vacuo; theresidue was chromatographed on a 50 g silica gel column, eluting with agradient from 1:1 ethyl acetate/hexanes to ethyl acetate, providing thetitle compound.

Compound 11

Compound 10 (58 mg, 0.06 mmol) was dissolved in 0.5 mL of chloroform;three drops of valeric anhydride was added, and the solution was stirredat ambient temperature for 3 hours. Reaction was quenched with aqueoussodium bicarbonate; the resultant mixture was stirred for 10 minutes.The organic phase was removed and concentrated in vacuo. The crudeproduct was purified by HPLC on a Waters Sunfire C8 column, eluting witha gradient of 60% to 100% acetonitrile in 0.1% ammonium acetate.

Compound 12

A solution of Compound C (1 mmol) in 20 mL of toluene was combined withpivaloyl chloride (0.18 g, 1.5 equivalents) and heated at 90° C. for 6hours. Reaction was quenched by addition of aqueous sodium bicarbonate,the resultant mixture was stirred for ten minutes. The organic layer wasseparated and washed with brine. The combined aqueous layers wasextracted with CHCl₃. The combined organic extracts were dried overNa₂SO₄, filtered, and concentrated. The residue was chromatographed on a50 g silica column, eluting with a gradient of 1:1 ethyl acetate/hexaneto 100% ethyl acetate to provide the title compound as a white solid.

Compound 13

Compound D (1 mmol) in 20 mL of toluene was combined with pivaloylchloride (0.24 g, 2.0 equivalents) and heated at 90° C. for 4 hours.Reaction was quenched by the addition of aqueous sodium bicarbonate, theresultant mixture was stirred for ten minutes. The organic layer wasseparated and washed with brine. The combined aqueous layers wasextracted with CHCl₃. The combined organic extracts were dried overNa₂SO₄, filtered, and concentrated. The residue was chromatographed on a50 g silica column, eluting with a gradient of 1:1 ethyl acetate/hexaneto 100% ethyl acetate to provide the title compound as a white solid.

Compound 14

Compound 12 (1.04 g, 1 mmol) was dissolved in methanol (20 mL). Themixture was heated at 65 ° C. for 40 hours and concentrated in vacuo toprovide the title compound as a white solid.

Compound 15

Compound C (2 mmol in 20 mL of toluene) was combined with 0.5 mL ofdiethylcarbamoyl chloride. The resultant solution was warmed at 80° C.for 40 hours. Solvents were removed in vacuo to reduce the volume byabout half. The remaining material was loaded onto a 50 g silica gelcolumn and eluted with a gradient from 1:1 ethyl acetate/hexanes to 100%ethyl acetate, to produce the title compound.

Compound 16

Compound 16 was prepared using the procedure for the preparation ofCompound 15, except for substituting N-methyl-N-phenylcarbamoyl chloridefor diethylcarbamoyl chloride. The resulting mixture was heated at 90°C. for 5 days. The crude material was purified by HPLC on a WatersSunfire C8 column, eluting with a gradient of 35%/50%/87%/100% methanolin 0.1% ammonium acetate.

Compound 17

Compound 17 was prepared using the procedure for the preparation ofCompound 15, except for substituting pyrrolidinecarbamoyl chloride fordiethylcarbamoyl chloride. The resulting mixture was heated at 90° C.for 5 hours. The crude material was purified by HPLC on a Waters SunfireC8 column, eluting with a gradient of 35%/50%/87%/100% methanol in 0.1%ammonium acetate.

Compound 18

Compound D (10 mmol) in 50 mL of toluene) was combined with 4.44 mL (3.5eq) of diethylcarbamoyl chloride. The resultant solution was warmed at80° C. for 40 hours. The reaction mixture was poured onto a pad of 40 gof silica gel and eluted with 2×80 mL washes of ethyl acetate. Thecombined washes were concentrated in vacuo; the residue was loaded ontoa 50 g silica gel column and eluted with a gradient from 1:1 ethylacetate/hexanes to 100% ethyl acetate, to produce the title compound.

Compound 19

Compound 15 (2.12 g, 2 mmol) was dissolved in 40 mL of methanol and themixture was warmed at 60° C. for three days. Solvents were removed invacuo to isolate the title compound.

Compound 20

Compound 20 was prepared using the procedure for the preparation ofCompound 15, except for substituting piperidinecarbamoyl chloride fordiethylcarbamoyl chloride, and the mixture was heated at 60° C. for 65hours. The crude product was purified by HPLC on a Waters Sunfire C8column, eluting with a gradient of 5%/50%/87%/100% methanol in 0.1%ammonium acetate.

Compound 21

Compound 21 was prepared using the procedure for the preparation ofCompound 15, except for substituting morpholinecarbamoyl chloride fordiethylcarbamoyl chloride, and the mixture was heated at 80° C. for 40hours. The crude product was purified by HPLC on a Waters Sunfire C8column, eluting with a gradient of 5%/50%/87%/100% methanol in 0.1%ammonium acetate.

Compound 22

Triphosgene (30 mg, 0.1 mmol) was dissolved in 0.5 mL of toluene; 0.1 mLof diisopropylamine was added with stirring. The solution warmed, and aprecipitate formed rapidly. After ten minutes, the resultant mixture waspushed through a syringe filter into a 4-ml vial. Compound C (0.2 mmolin 2 mL of toluene) was added, and the resultant mixture was warmed at90° C. for 40 hours. Solvents were removed in vacuo to reduce the volumeby about half; the remaining material was loaded onto a 10 g silica gelcolumn and eluted with a gradient from 1:1 ethyl acetate/hexanes to 100%ethyl acetate.

Compound 23

Compound 23 was prepared using the procedure for the preparation ofCompound 22, except for substituting di-n-butylamine fordiisopropylamine.

Compound 24

Compound 24 was prepared using the procedure for the preparation ofCompound 22, except for substituting diisobutylamine fordiisopropylamine.

Compound 25

Compound 25 was prepared using the procedure for the preparation ofCompound 22, except for substituting hexamethyleneimine fordiisopropylamine.

Compound 26

Compound 26 was prepared using the procedure for the preparation ofCompound 22, except for substituting dicyclohexylamine fordiisopropylamine.

Compound 27

Compound 27 was prepared using the procedure for the preparation ofCompound 15, except for substituting dimethylcarbamoyl chloride fordiethylcarbamoyl chloride, and substituting Compound D for Compound C.

Compound 28

Compound 28 was prepared using the procedure for the preparation ofCompound 22, except for substituting N-ethyl-N-butylamine fordiisopropylamine, and substituting Compound D for Compound C. Theresultant mixture was heated at 80° C. for 40 hours.

Compound 29

Compound 22 (30 mg) was dissolved in 1.5 mL of methanol and the mixturewas warmed at 90° C. for 4 hours. The crude product was purified by HPLCon a Waters Sunfire C8 column, eluting with a gradient of 35% to 65%acetonitrile in 0.1% ammonium acetate.

Compound 30

Compound 23 (30 mg) was dissolved in 2 mL of methanol and the mixturewas warmed at 70° C. for 65 hours. The crude product was purified byHPLC on a Waters Sunfire C8 column, eluting with a gradient of 35% to65% acetonitrile in 0.1% aqueous ammonium acetate.

Compound 31

Compound 26 (54 mg) was dissolved in 1.5 mL of methanol and the mixturewas warmed at 90° C. for 4 hours. Solvents were removed in vacuo to givethe title compound as a white solid.

Compound 32

Compound D (1.5 mmol) in 10 mL toluene solution, was combined withmorpholine-carbamoyl chloride (0.6 mL, 3.5 equivalents); the resultantmixture was heated overnight at 80° C. Solvents were removed in vacuo:the residue was chromatographed on a 50 g silica gel column, elutingwith a gradient from 1:1 ethyl acetate/hexanes to 100% ethyl acetate, toproduce the title compound.

Compound 33

Compound C (1.5 mmol) in 10 mL toluene solution, was combined with2,4-difluorobenzyl bromide (2.0 equivalents) and 30 mg oftetra-n-butylammonium iodide. The resultant mixture was heated at 90° C.for 3 days. Solvents were removed in vacuo; the residue waschromatographed on a 50 g silica gel column, eluting with a gradientfrom 1:1 ethyl acetate/hexanes to 100% ethyl acetate. The title compoundwas collected as a white solid.

Compound 34

Compound F (1.5 mmol) in 10 mL toluene solution, was combined withmorpholine-carbamoyl chloride (0.6 mL, 3.5 equivalents); the resultantmixture was heated at 90° C. for 8 hours. Solvents were removed invacuo; the residue was chromatographed on a 100 g silica gel column,eluting with a gradient from 1:1 ethyl acetate/hexanes to 100% ethylacetate, to produce the title compound.

Compound 35

Compound F (1.5 mmol) in 10 mL toluene solution, was combined with2,4-difluorobenzyl bromide (2.0 equivalents) and 100 mg oftetra-n-butylammonium iodide. The resultant mixture was heated at 90° C.for 3 days. Solvents were removed in vacuo: the residue waschromatographed on a 50 g silica gel column, eluting with a gradientfrom 1:1 ethyl acetate/hexanes to 100% ethyl acetate. The title compoundwas collected as a white solid.

Compound 36

Compound 21 (0.92 g) was dissolved in 20 mL of methanol; 20 mg of solidsodium bicarbonate was added, and the resultant mixture was warmed at50° C. for 40 hours. Solvents were removed in vacuo; the residue wastaken up in ethyl acetate and filtered through a syringe filter. Thesolution was concentrated in vacuo to give the title compound.

Compound 37

Compound 33 (0.54 g) was dissolved in 20 mL of methanol; 20 mg of solidsodium bicarbonate was added, and the resultant mixture was warmed at70° C. for 40 hours. Solvents were removed in vacuo; the residue wastaken up in ethyl acetate and filtered through a syringe filter. Thesolution was concentrated in vacuo to give the title compound.

Compound 38

Compound 1 (1.05 g, 1 mmol) was dissolved in methanol (20 mL) and heatedat 65° C. for 40 hours. Solvents were removed in vacuo to provide thetitle compound.

Compound 39

Step 1: The intermediate was prepared using the procedure for thepreparation of Compound 1, except for substituting 4-methoxybenzylbromide for benzyl bromide.

Step 2: Compound 39 was prepared using the procedure for the preparationof Compound 38, except for substituting the intermediate obtained fromStep 1 for Compound 1. The crude product was purified by HPLC on aWaters Sunfire C8 column, eluting with a gradient of 35%/65%/87%/100%acetonitrile in 0.1% ammonium acetate.

Compound 40

Compound 19 (200 mg) was combined with 20 mg of 10% palladium-on-carbonin 12 mL of methanol; the resultant mixture was first purged undernitrogen, then exchanged for a balloon of hydrogen gas. After stirringat ambient temperature for 4 hours, the balloon was removed, the mixturewas purged with nitrogen and concentrated in vacuo. The residue wastaken up in ethyl acetate and passed through a 0.45 micron filter toremove the catalyst. The resultant clear solution was concentrated invacuo to give the title compound.

Compound 41

Compound 18 (200 mg) was combined with 20 mg of 10% palladium-on-carbonin 12 mL of methanol; the resultant mixture was first purged undernitrogen, then exchanged for a balloon of hydrogen gas. After stirringat ambient temperature for 4 hours, the balloon was removed, the mixturewas purged with nitrogen and concentrated in vacuo. The residue wastaken up in ethyl acetate and passed through a 0.45 micron filter toremove the catalyst. The resultant clear solution was concentrated invacuo to give the title compound.

Compound 42

Compound J (0.83 mmol) was combined with 4-fluorobenzyl bromide (1.5 eq)and 0.1 eq of tetra-n-butylammonium iodide. The resultant mixture washeated at 90° C. for two days. The mixture was concentrated in vacuo;the residue was chromatographed on silica gel, eluting with a gradientof 20-100% ethyl acetate/hexanes. Fractions containing the targetcompound (as its 2′-acetate) were combined and concentrated in vacuo.The residue was dissolved in 15 mL of methanol; 20 mg of solid sodiumbicarbonate was added, and the resultant solution was stirred overnightat 40° C. The mixture was concentrated in vacuo; the residue waschromatographed on silica gel, eluting with a gradient of 50-100% ethylacetate/hexanes. The title compound (112 mg) was isolated as a whitefoam.

Compound 43

Compound J (0.83 mmol) was combined with 2,4-difluorobenzyl bromide (1.5eq) and 0.1 eq of tetra-n-butylammonium iodide. The resultant mixturewas heated at 90° C. for two days. The mixture was concentrated invacuo; the residue was chromatographed on silica gel, eluting with agradient of 20-100% ethyl acetate/hexanes. Fractions containing thetarget compound (as its 2′-acetate) were combined and concentrated invacuo. The residue was dissolved in 15 mL of methanol; 20 mg of solidsodium bicarbonate was added, and the resultant solution was stirredovernight at 40° C. The mixture was concentrated in vacuo; the residuewas chromatographed on silica gel, eluting with a gradient of 50-100%ethyl acetate/hexanes. The title compound (50 mg) was isolated as awhite foam.

Compound 44

Compound 15 (200 mg) was dissolved in 1 mL of dry pyridine; 0.2 mL ofpropionic anhydride was added, and the resulting solution was stirred atambient temperature for 2 hours. Reaction was quenched by the additionof 0.5 mL of methanol; the mixture was stirred for 10 minutes, thenconcentrated in vacuo. The residue was chromatographed on a 10 g silicagel column, eluting with a solvent gradient from 20% ethylacetate/hexanes to ethyl acetate. A pure sample (20 mg) selected from amiddle cut of the major peak was confirmed to be the title compound.

Compound 45

Compound 44 (60 mg) was dissolved in 5 mL of methanol and heated atreflux for 12 hours. Sovents were removed in vacuo; the residue waspurified by HPLC on a Waters Sunfire C8 column, eluting with a gradientof 50% to 100% acetonitrile in 0.1% ammonium acetate. The title compoundwas isolated as a white solid (23 mg).

Compound 46

The title compound was isolated as a minor fraction (5 mg) from HPLCpurification of the mixture generated during the reaction to produceCompound 45.

Compound 47

Compound 3 (435 mg) was dissolved in 2 mL of dry pyridine; 0.4 mL ofpropionic anhydride was added, and the resulting solution was stirred atambient temperature for 2 hours. Reaction was quenched by the additionof 0.5 mL of methanol; the mixture was stirred for 10 minutes, thenconcentrated in vacuo. The residue was chromatographed on a 40g silicagel column, eluting with a solvent gradient from 20% ethylacetate/hexanes to ethyl acetate. A pure sample (13 mg) selected from amiddle cut of the major peak was confirmed to be the title compound.

Compound 48

Compound 47 (77 mg) was dissolved in 2 mL of methanol and warmed at 60°C. for 5 days. Sovents were removed in vacuo; the residue was purifiedby HPLC on a Waters Sunfire C8 column, eluting with a gradient of 50% to100% acetonitrile in 0.1% ammonium acetate. The title compound wasisolated as a white solid (11 mg).

Compound 49

Compound 15 (400 mg) was dissolved in 2 mL of dry pyridine; 0.4 mL ofacetic anhydride was added, and the resulting solution was stirred atambient temperature for 3 hours. Reaction was quenched by the additionof 0.5 mL of methanol; the mixture was stirred for 10 minutes, thenconcentrated in vacuo. The residue was chromatographed on a 10 g silicagel column, eluting with a solvent gradient from 20% ethylacetate/hexanes to ethyl acetate. A set of mixed fractions wereconcentrated in vacuo and re-purified by HPLC on a Waters Sunfire C8column, eluting with a gradient of 50% to 100% acetonitrile in 0.1%ammonium acetate. The title compound was isolated as a white solid (18.4mg).

Compound 50

Compound 49 (330 mg) was dissolved in 5 mL of methanol and warmed at 70°C. for 3 days. Sovents were removed in vacuo; the residue was purifiedby chromatography on a 12-g silica gel column, eluting with a gradientfrom 60% ethyl acetate in hexanes to 100% ethyl acetate. The resultantimpure fractions were re-purified by HPLC on a Waters Sunfire C8 column,eluting with a gradient of 50% to 100% acetonitrile in 0.1% ammoniumacetate. The title compound was isolated as a white solid (64.9 mg).

Compound 51

Compound 15 (400 mg) was dissolved in 2 mL of dry pyridine; 0.4 mL ofisobutyric anhydride was added, and the resulting solution was stirredat ambient temperature for 24 hours. Reaction was quenched by theaddition of 0.5 mL of methanol; the mixture was stirred for 10 minutes,then concentrated in vacuo. The residue was chromatographed on a 12 gsilica gel column, eluting with a solvent gradient from 20% ethylacetate/hexanes to ethyl acetate. The resultant product (350 mg) wasdissolved in 5 mL of methanol and warmed at 70 C for 3 days. Soventswere removed in vacuo; the residue was purified by chromatography on a12-g silica gel column, eluting with a gradient from 20% ethyl acetatein hexanes to 100% ethyl acetate. The resultant impure sample wasre-purified by HPLC on a Waters Sunfire C8 column, eluting with a slowgradient of 2% to 100% acetonitrile in 0.1% ammonium acetate. The titlecompound was isolated as a white solid (88.5 mg).

Compound 52

Compound 3 (400 mg) was dissolved in 2 mL of dry pyridine; 0.1 mL ofacetic anhydride was added, and the resulting solution was stirred atambient temperature for 4 hours. Reaction was quenched by the additionof 0.5 mL of methanol; the mixture was stirred for 10 minutes, thenconcentrated in vacuo. The residue was chromatographed on a 12g silicagel column, eluting with a solvent gradient from 20% ethylacetate/hexanes to ethyl acetate. A pure sample (17 mg) selected from amiddle cut of the major peak was confirmed to be the title compound.

Compound 53

Compound 52 (180 mg) was dissolved in 5 mL of methanol and warmed at 70°C. for 3 days. Sovents were removed in vacuo; the residue was purifiedby chromatography on a 12-g silica gel column, eluting with a gradientfrom 60% ethyl acetate in hexanes to 100% ethyl acetate. The titlecompound was isolated as a white solid (141 mg).

Compound 54

Compound 3 (400 mg) was dissolved in 2 mL of dry pyridine; 0.4 mL ofisobutyric anhydride was added, and the resulting solution was stirredat ambient temperature for 20 hours. Reaction was quenched by theaddition of 0.5 mL of methanol; the mixture was stirred for 10 minutes,then concentrated in vacuo. The residue was chromatographed on a 12 gsilica gel column, eluting with a solvent gradient from 60% ethylacetate/hexanes to ethyl acetate. A pure sample (6.4 mg) selected from amiddle cut of the major peak was confirmed to be the title compound.

Compound 55

Compound 54 (190 mg) was dissolved in 5 mL of methanol and warmed at 60°C. for 4 days. Sovents were removed in vacuo; the residue was purifiedby chromatography on a 12-g silica gel column, eluting with a gradientfrom 60% ethyl acetate in hexanes to 100% ethyl acetate. The titlecompound was isolated as a white solid (140 mg).

It is understood that the foregoing detailed description andaccompanying examples are merely illustrative and are not to be taken aslimitations upon the scope of the invention, which is defined solely bythe appended claims and their equivalents. Various changes andmodifications to the disclosed embodiments will be apparent to thoseskilled in the art. Such changes and modifications, including withoutlimitation those relating to the chemical structures, substituents,derivatives, intermediates, syntheses, formulations, or methods, or anycombination of such changes and modifications of use of the invention,may be made without departing from the spirit and scope thereof.

All references (patent and non-patent) cited above are incorporated byreference into this patent application. The discussion of thosereferences is intended merely to summarize the assertions made by theirauthors. No admission is made that any reference (or a portion of anyreference) is relevant prior art (or prior art at all). Applicantsreserve the right to challenge the accuracy and pertinence of the citedreferences.

What is claimed is:
 1. A method of preventing or treating filariasis ina subject in need thereof, comprising: administering to the subject atherapeutically effective amount of a macrolide antibiotic.
 2. Themethod of claim 1, wherein the macrolide antibiotic is tylosin A or asalt thereof.
 3. The method of claim 1, wherein the subject is a human.4. The method of claim 1, wherein the filariasis is lymphatic filariasisor subcutaneous filariasis.
 5. The method of claim 1, wherein thefilariasis is caused by Onchocerca volvulus, Wuchereria bancrofti,Brugia malayi, Brugia timori, or Dirofilaria immitis.
 6. A method ofpreventing or treating filariasis caused by Onchocerca volvulus,Wuchereria bancrofti, Brugia malayi, Brugia timori, or Dirofilariaimmitis in a subject in need thereof, comprising: administering to thesubject a therapeutically effective amount of a compound of Formula (I):

or a salt thereof, wherein: R₁ represents hydrogen or —C(O)R₃, whereinR₃ represents an optionally substituted C₁-C₆-alkyl or C₁-C₆-haloalkyl;R₂ represents —C(O)C(R₄)(R₅)(R₆), wherein R₄ is selected from the groupconsisting of hydrogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, aryl, heteroaryl,C₃-C₈-cycloalkyl, heterocycloalkyl, arylalkyl, heteroarylalkyl, andC₃-C₈-cycloalkyl-C₁-C₄-alkyl; and each of R₅ and R₆ are independentlyselected from the group consisting of C₁-C₆-alkyl, C₁-C₆-haloalkyl,aryl, heteroaryl, C₃-C₈-cycloalkyl, heterocycloalkyl, arylalkyl,heteroarylalkyl, and C₃-C₈-cycloalkyl-C₁-C₄-alkyl; or R₂ represents—C(O)N(R₇)(R₈), wherein each of R₇ and R₈ are independently selectedfrom the group consisting of hydrogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl,aryl, heteroaryl, C₃-C₈-cycloalkyl, heterocycloalkyl, arylalkyl,heteroarylalkyl, and C₃-C₈-cycloalkyl-C₁-C₄-alkyl, or R₇ and R₈ togetherwith the nitrogen atom to which they are attached form an optionallysubstituted saturated or partially saturated heterocyclic ring; or R₂represents —CH₂-A₁, wherein A₁ represents a 6- to 10-membered aryl or a5- to 10-membered heteroaryl and A₁ is unsubstituted or substituted withone or more R_(A), wherein each R_(A) is independently selected from thegroup consisting of halogen, C₁-C₆-alkyl, C₁-C₆-haloalkyl, and —O—R₉,where R₉ represents C₁-C₆-alkyl; R₁₀ represents hydrogen or —C(O)R₁₁,wherein R₁₁ represents an optionally substituted C₁-C₆-alkyl,C₁-C₆-haloalkyl, aryl, heteroaryl, C₃-C₈-cycloalkyl, heterocycloalkyl,arylalkyl, heteroarylalkyl, or C₃-C₈-cycloalkyl-C₁-C₄-alkyl; and each ofa and b independently represents either a single bond or a double bond.7. The method of claim 6, wherein R₁₀ is —C(O)R₁₁.
 8. The method ofclaim 7, wherein R₁₁ is C₁-C₆-alkyl.
 9. The method of claim 7, whereinboth a and b represent a double bond and wherein R₁ is —C(O)CH₃, R₂ is—C(O)N(CH₂CH₃)₂, and R₁₁ is —CH₂CH₃; R₁ is hydrogen, R₂ is—C(O)N(CH₂CH₃)₂, and R₁₁ is —CH₂CH₃; R₁ is —C(O)CH₂CH₃, R₂ is—C(O)N(CH₂CH₃)₂, and R₁₁ is —CH₂CH₃; R₁ is —C(O)CH₃, R₂ is

and R₁₁ is —CH₂CH₃; R₁ is hydrogen, R₂ is

and R₁₁ is —CH₂CH₃; R₁ is —C(O)CH₃, R₂ is —C(O)N(CH₂CH₃)₂, and R₁₁ is—CH₃; R₁ is hydrogen, R₂ is —C(O)N(CH₂CH₃)₂, and R₁₁ is —CH₃; R₁ ishydrogen, R₂ is —C(O)N(CH₂CH₃)₂, and R₁₁ is —CH(CH₃)₂; R₁ is —C(O)CH₃,R₂ is

and R₁₁ is —CH₃; R₁ is hydrogen, R₂ is

and R₁₁ is —CH₃; R₁ —C(O)CH₃, R₂ is

and R₁₁ is —CH(CH₃)₂; or R₁ is hydrogen, R₂ is

and R₁₁ is —CH(CH₃)₂.
 10. The method of claim 6, wherein the compoundhas a structure corresponding to Formula (I-1):

or a salt thereof.
 11. The method of claim 10, wherein R₁ is hydrogen.12. The method of claim 10, wherein R₁ is —C(O)R₃.
 13. The method ofclaim 12, wherein R₃ is methyl, isopropyl, or n-butyl.
 14. The method ofclaim 10, wherein R₂ is —C(O)N(R₇)(R₈) and each of R₇ and R₈ areindependently selected from the group consisting of C₁-C₆-alkyl, aryl,and C₃-C₈-cycloalkyl, or R₇ and R₈ together with the nitrogen atom towhich they are attached form an optionally substituted saturated orpartially saturated heterocyclic ring.
 15. The method of claim 14,wherein the heterocyclic ring is a pyrrolidine, a piperidine, anazepane, or a morpholine.
 16. The method of claim 10, wherein R₂ is—CH₂-A₁ and A₁ is an unsubstituted phenyl or a phenyl substituted withone or more R_(A).
 17. The method of claim 16, wherein R_(A) is halogen.18. The method of claim 10, wherein both a and b represent a doublebond.
 19. The method of claim 18, wherein R₁ is —C(O)CH₃ and R₂ is

R₁ is —C(O)CH₃ and R₂ is

R₁ is —C(O)CH₃ and R₂ is

R₁ is —C(O)CH₃ and R₂ is

R₁ is —C(O)CH(CH₃)₂ and R₂ is

R₁ is —C(O)CH(CH₃)₂ and R₂ is

R₁ is —C(O)CH(CH₃)₂ and R₂ is

R₁ is —C(O)CH(CH₃)₂ and R₂ is

R₁ is —C(O)CH(CH₃)₂ and R₂ is

R₁ is hydrogen and R₂ is

R₁ is —C(O)(CH₂)₃CH₃ and R₂ is

R₁ is —C(O)CH₃ and R₂ is —C(O)C(CH₃)₃; R₁ is —C(O)CH(CH₃)₂ and R₂ is—C(O)C(CH₃)₃; R₁ is hydrogen and R₂ is —C(O)C(CH₃)₃; R₁ is —C(O)CH₃ andR₂ is —C(O)N(CH₂CH₃)₂; R₁ is —C(O)CH₃ and R₂ is —C(O)N(CH₃)(C₆H₅); R₁ is—C(O)CH₃ and R₂ is

R₁ is —C(O)CH(CH₃)₂ and R₂ is —C(O)N(CH₂CH₃)₂; R₁ is hydrogen and R₂ is—C(O)N(CH₂CH₃)₂; R₁ is —C(O)CH₃ and R₂ is

R₁ is —C(O)CH₃ and R₂ is

R₁ is —C(O)CH₃ and R₂ is —C(O)N(CH(CH₃)₂)₂; R₁ is —C(O)CH₃ and R₂ is—C(O)N((CH₂)₃CH₃)₂; R₁ is —C(O)CH₃ and R₂ is —C(O)N((CH₂CHCH₃)₂)₂; R₁ is—C(O)CH₃ and R₂ is

R₁ is —C(O)CH₃ and R₂ is

R₁ is —C(O)CH(CH₃)₂ and R₂ is —C(O)N(CH₃)₂; R₁ is —C(O)CH(CH₃)₂ and R₂is —C(O)N(CH₂CH₃)((CH₂)₃CH₃); R₁ is hydrogen and R₂ is—C(O)N(CH(CH₃)₂)₂; R₁ is hydrogen and R₂ is —C(O)N((CH₂)₃CH₃)₂; R₁ is Hand R₂ is

R₁ is —C(O)CH(CH₃)₂ and R₂ is

R₁ is —C(O)CH₃ and R₂ is

R₁ is —C(O)(CH₂)₃(CH₃) and R₂ is

R₁ is —C(O)(CH₂)₃(CH₃) and R₂ is

R₁ is hydrogen and R₂ is

R₁ is hydrogen and R₂ is

R₁ is hydrogen and R₂ is

or R₁ is hydrogen and R₂ is


20. The method of claim 18, wherein R₁ is hydrogen and R₂ is

or —C(O)N(CH₂CH₃)₂.
 21. The method of claim 10, wherein both a and brepresent a single bond.
 22. The method of claim 21, wherein R₁ ishydrogen and R₂ is —C(O)N(CH₂CH₃)₂; R₁ is —C(O)CH(CH₃)₂ and R₂ is—C(O)N(CH₂CH₃)₂; R₁ is hydrogen and R₂ is

or R₁ is hydrogen and R₂ is